Dapper的完整扩展(转)

真心想说：其实。。。我不想用Dapper，如果OrmLite.Net支持参数化的话，也就没Dapper的什么事情了，对于OrmLite.Net只能做后续跟踪......

这个其实是看了Dapper作者的扩展后觉得不爽，然后自己按照他的设计思路重写了代码，只支持单个数据的增删改查，根据Expression来查的真心无能为力......

另外作者似乎已经支持了属性、字段等与数据库中的映射.....

具体包含了

1、对字符串的扩展

2、对主键的定义，支持单或多主键，当单主键并且类型为数字时，认为该主键为自增列

3、对表名的定义

 

实际代码如下：

DapperExtensions部分

using System;  
using System.Collections.Generic;  
using System.Linq;  
using System.Text;  
using System.Data;  
using System.Collections.Concurrent;  
using System.Reflection;  
  
namespace Dapper  
{  
    /// <summary>  
    /// Dapper扩展POCO信息类，为应用此扩展，在原Dapper的第1965行增加了对此类的应用  
    /// </summary>  
    public class DapperPocoInfo  
    {  
        private Type _type;  
        private ConcurrentDictionary<string, KeyValuePair<DbType, int>> _stringColumns  
            = new ConcurrentDictionary<string, KeyValuePair<DbType, int>>();  
        private IEnumerable<PropertyInfo> _typeProperties;  
        private IList<PropertyInfo> _keyProperties = new List<PropertyInfo>();  
        private IEnumerable<PropertyInfo> _defaultKeyPropeties;  
        private string _tableName;  
        /// <summary>  
        /// 对应表名  
        /// </summary>  
        public string TableName  
        {  
            get  
            {  
                if (string.IsNullOrWhiteSpace(this._tableName))  
                {  
                    this._tableName = this._type.Name;  
                }  
                return this._tableName;  
            }  
            set  
            {  
                this._tableName = value;  
            }  
        }  
        /// <summary>  
        /// 所有Public的属性集合  
        /// </summary>  
        public IEnumerable<PropertyInfo> TypeProperties  
        {  
            get { return this._typeProperties; }  
        }  
        /// <summary>  
        /// 获取主键集合，如果主键数量大于1，则认为是联合主键，等于0认为不存在主键，等于1并且类型为数字型则认为自增主键  
        /// </summary>  
        /// <returns></returns>  
        public IEnumerable<PropertyInfo> KeyProperties  
        {  
            get  
            {  
                if (this._keyProperties.Count == 0)  
                {//如果未设定KeyProperties，则默认认为第一个后缀为ID的PropertyInfo为主键  
                    if (this._defaultKeyPropeties == null)  
                    {  
                        this._defaultKeyPropeties = this._typeProperties.Where(p => p.Name.ToLower().EndsWith("id")).Take(1).ToArray();  
                    }  
                    return this._defaultKeyPropeties;  
                }  
                else  
                {  
                    return this._keyProperties;  
                }  
            }  
        }  
        /// <summary>  
        /// .oct  
        /// </summary>  
        /// <param name="type"></param>  
        internal DapperPocoInfo(Type type)  
        {  
            if (type == null)  
            {  
                throw new ArgumentNullException();  
            }  
            this._type = type;  
            this._typeProperties = type.GetProperties();  
        }  
        /// <summary>  
        /// 添加字符串参数化映射  
        /// </summary>  
        /// <param name="propertyName">属性名</param>  
        /// <param name="dbType">必须为AnsiString、AnsiStringFixedLength、String、StringFixedLength</param>  
        /// <param name="len">值范围为1~8000</param>  
        public virtual void AddStringColumnMap(string propertyName, DbType dbType = DbType.AnsiString, int len = 50)  
        {  
            this.GetProperty(propertyName);  
            if (len <= 0 || len > 8000)  
            {//长度范围1~8000,此处暂时对应sql，如果其它关系型数据库长度范围与此不一致，可继承修改  
                throw new ArgumentException("The param len's value must between 1 and 8000.");  
            }  
            if (dbType != DbType.AnsiString && dbType != DbType.AnsiStringFixedLength && dbType != DbType.String && dbType != DbType.StringFixedLength)  
            {  
                return;  
            }  
            this._stringColumns.TryAdd(propertyName, new KeyValuePair<DbType, int>(dbType, len));  
        }  
        /// <summary>  
        /// 获取字符串映射  
        /// </summary>  
        /// <param name="propertyName"></param>  
        /// <returns></returns>  
        public KeyValuePair<DbType, int>? GetStringColumnMap(string propertyName)  
        {  
            KeyValuePair<DbType, int> kvp;  
            if (this._stringColumns.TryGetValue(propertyName, out kvp))  
            {  
                return kvp;  
            }  
            return null;  
        }  
        private PropertyInfo GetProperty(string propertyName)  
        {  
            if (string.IsNullOrWhiteSpace(propertyName))  
            {  
                throw new ArgumentNullException("propertyName can not be null or empty value");  
            }  
            PropertyInfo pi = this._typeProperties.Where(p => p.Name.ToLower() == propertyName.ToLower()).FirstOrDefault();  
            if (pi == null)  
            {  
                throw new ArgumentOutOfRangeException(string.Format("The class '{0}' does not contains property '{1}'.", this._type.FullName, propertyName));  
            }  
            return pi;  
        }  
        /// <summary>  
        /// 添加主键映射  
        /// </summary>  
        /// <param name="propertyName"></param>  
        public void AddKeyMap(string propertyName)  
        {  
            var pi = this.GetProperty(propertyName);  
            if (this._keyProperties.Where(p => p.Name == pi.Name).FirstOrDefault() == null)  
            {  
                this._keyProperties.Add(pi);  
                this._unWriteKey = null;//赋值时取消已经确认的是否可写键值  
            }  
        }  
        /// <summary>  
        /// 不需要插入数据的主键类型，除了Guid，其它均认为自增  
        /// </summary>  
        private static Type[] UnWriteTypes = { typeof(int), typeof(short), typeof(long), typeof(byte), typeof(Guid) };  
        private bool? _unWriteKey;  
        /// <summary>  
        /// 主键是否可写  
        /// </summary>  
        /// <returns></returns>  
        public bool IsUnWriteKey()  
        {  
            if (!this._unWriteKey.HasValue)  
            {  
                this._unWriteKey = false;  
                IList<PropertyInfo> keys = this.KeyProperties.ToList();  
                if (keys.Count == 1)  
                {  
                    this._unWriteKey = UnWriteTypes.Contains(keys[0].PropertyType);  
                }  
            }  
            return this._unWriteKey.Value;  
        }  
    }  
    /// <summary>  
    /// Dapper扩展类  
    /// </summary>  
    public static class DapperExtensions  
    {  
        private static ConcurrentDictionary<RuntimeTypeHandle, DapperPocoInfo> PocoInfos  
            = new ConcurrentDictionary<RuntimeTypeHandle, DapperPocoInfo>();  
        /// <summary>  
        /// 已实现的ISqlAdapter集合  
        /// </summary>  
        private static readonly Dictionary<string, ISqlAdapter> AdapterDictionary  
            = new Dictionary<string, ISqlAdapter>() {  
            {"sqlconnection", new MsSqlServerAdapter()}  
            };  
  
        public static DapperPocoInfo GetPocoInfo<T>()  
            where T : class  
        {  
            return GetPocoInfo(typeof(T));  
        }  
        public static DapperPocoInfo GetPocoInfo(this Type type)  
        {  
            DapperPocoInfo pi;  
            RuntimeTypeHandle hd = type.TypeHandle;  
            if (!PocoInfos.TryGetValue(hd, out pi))  
            {  
                pi = new DapperPocoInfo(type);  
                PocoInfos[hd] = pi;  
            }  
            return pi;  
        }  
  
        public static ISqlAdapter GetSqlAdapter(this IDbConnection connection)  
        {  
            string name = connection.GetType().Name.ToLower();  
            ISqlAdapter adapter;  
            if (!AdapterDictionary.TryGetValue(name, out adapter))  
            {  
                throw new NotImplementedException(string.Format("Unknow sql connection '{0}'", name));  
            }  
            return adapter;  
        }  
  
        /// <summary>  
        /// 新增数据，如果T只有一个主键，且新增的主键为数字，则会将新增的主键赋值给entity相应的字段，如果为多主键，或主键不是数字和Guid,则主键需输入  
        /// 如果要进行匿名类型新增，因为匿名类型无法赋值，需调用ISqlAdapter的Insert，由数据库新增的主键需自己写方法查询  
        /// </summary>  
        /// <typeparam name="T"></typeparam>  
        /// <param name="connection"></param>  
        /// <param name="entity"></param>  
        /// <param name="transaction"></param>  
        /// <param name="commandTimeout"></param>  
        /// <returns></returns>  
        public static bool Insert<T>(this IDbConnection connection, T entity, IDbTransaction transaction = null, int? commandTimeout = null)  
            where T : class  
        {  
            ISqlAdapter adapter = GetSqlAdapter(connection);  
            return adapter.Insert<T>(connection, entity, transaction, commandTimeout);  
        }  
        /// <summary>  
        /// 更新数据，如果entity为T,则全字段更新，如果为匿名类型，则修改包含的字段，但匿名类型必须包含主键对应的字段  
        /// </summary>  
        /// <typeparam name="T"></typeparam>  
        /// <param name="connection"></param>  
        /// <param name="entity"></param>  
        /// <param name="transaction"></param>  
        /// <param name="commandTimeout"></param>  
        /// <returns></returns>  
        public static bool Update<T>(this IDbConnection connection, object entity, IDbTransaction transaction = null, int? commandTimeout = null)  
            where T : class  
        {  
            ISqlAdapter adapter = GetSqlAdapter(connection);  
            return adapter.UpdateByKey<T>(connection, entity, transaction, commandTimeout);  
        }  
        /// <summary>  
        /// 删除数据，支持匿名，但匿名类型必须包含主键对应的字段  
        /// </summary>  
        /// <typeparam name="T"></typeparam>  
        /// <param name="connection"></param>  
        /// <param name="param"></param>  
        /// <param name="transaction"></param>  
        /// <param name="commandTimeout"></param>  
        /// <returns></returns>  
        public static bool DeleteByKey<T>(this IDbConnection connection, object param, IDbTransaction transaction = null, int? commandTimeout = null)  
            where T : class  
        {  
            ISqlAdapter adapter = GetSqlAdapter(connection);  
            return adapter.DeleteByKey<T>(connection, param, transaction, commandTimeout);  
        }  
        /// <summary>  
        /// 查询数据，支持匿名，但匿名类型必须包含主键对应的字段  
        /// </summary>  
        /// <typeparam name="T"></typeparam>  
        /// <param name="connection"></param>  
        /// <param name="param"></param>  
        /// <param name="transaction"></param>  
        /// <param name="commandTimeout"></param>  
        /// <returns></returns>  
        public static T QueryByKey<T>(this IDbConnection connection, object param, IDbTransaction transaction = null, int? commandTimeout = null)  
            where T : class  
        {  
            ISqlAdapter adapter = GetSqlAdapter(connection);  
            return adapter.QueryByKey<T>(connection, param, transaction, commandTimeout);  
        }  
        /// <summary>  
        /// 获取最后新增的ID值，仅对Indentity有效  
        /// </summary>  
        /// <typeparam name="T"></typeparam>  
        /// <param name="connection"></param>  
        /// <returns></returns>  
        public static long GetLastInsertIndentityID<T>(this IDbConnection connection)  
            where T : class  
        {  
            ISqlAdapter adapter = GetSqlAdapter(connection);  
            return adapter.GetLastInsertID<T>(connection);  
        }  
    }  
  
    public interface ISqlAdapter  
    {  
        string GetFullQueryByKeySql(Type type);  
        string GetFullInsertSql(Type type);  
        string GetFullUpdateByKeySql(Type type);  
        string GetDeleteByKeySql(Type type);  
        bool Insert<T>(IDbConnection connection, object entity, IDbTransaction transaction, int? commandTimeout)  
            where T : class;  
        bool UpdateByKey<T>(IDbConnection connection, object entity, IDbTransaction transaction, int? commandTimeout)  
            where T : class;  
        bool DeleteByKey<T>(IDbConnection connection, object param, IDbTransaction transaction, int? commandTimeout)  
            where T : class;  
        T QueryByKey<T>(IDbConnection connection, object param, IDbTransaction transaction, int? commandTimeout)  
            where T : class;  
        long GetLastInsertID<T>(IDbConnection connection)  
            where T : class;  
    }  
  
    internal class BasicSql  
    {  
        public string FullQueryByKeySql { get; set; }  
        public string FullInsertSql { get; set; }  
        public string FullUpdateByKeySql { get; set; }  
        public string DeleteByKeySql { get; set; }  
    }  
  
    public class MsSqlServerAdapter : ISqlAdapter  
    {  
        private static ConcurrentDictionary<RuntimeTypeHandle, BasicSql> BasicSqls  
            = new ConcurrentDictionary<RuntimeTypeHandle, BasicSql>();  
        private static readonly char SqlParameterChar = '@';  
  
        internal MsSqlServerAdapter() { }  
  
        private string GetParameterName(PropertyInfo pi)  
        {  
            return string.Format("{0}{1}", SqlParameterChar, pi.Name);  
        }  
        private BasicSql GetBasicSql(Type type)  
        {  
            BasicSql basicSql;  
            RuntimeTypeHandle hd = type.TypeHandle;  
            if (!BasicSqls.TryGetValue(hd, out basicSql))  
            {  
                basicSql = new BasicSql();  
                BasicSqls[hd] = basicSql;  
            }  
            return basicSql;  
        }  
        private void AppendKeyParameter(StringBuilder tmp, IEnumerable<PropertyInfo> keys)  
        {  
            if (keys.Any())  
            {  
                tmp.AppendLine(" WHERE");  
                foreach (PropertyInfo key in keys)  
                {  
                    tmp.Append(key.Name);  
                    tmp.Append("=");  
                    tmp.Append(this.GetParameterName(key));  
                    tmp.Append(" AND ");  
                }  
                tmp.Remove(tmp.Length - 5, 5);  
            }  
        }  
        public string GetFullQueryByKeySql(Type type)  
        {  
            BasicSql basicSql = this.GetBasicSql(type);  
            if (string.IsNullOrEmpty(basicSql.FullQueryByKeySql))  
            {  
                DapperPocoInfo dpi = type.GetPocoInfo();  
                StringBuilder tmp = new StringBuilder();  
                tmp.Append("SELECT * FROM ");  
                tmp.Append(dpi.TableName);  
                tmp.Append(" (NOLOCK) ");  
                this.AppendKeyParameter(tmp, dpi.KeyProperties);  
                basicSql.FullQueryByKeySql = tmp.ToString();  
            }  
            return basicSql.FullQueryByKeySql;  
        }  
  
        public string GetFullInsertSql(Type type)  
        {  
            BasicSql basicSql = this.GetBasicSql(type);  
            if (string.IsNullOrEmpty(basicSql.FullInsertSql))  
            {  
                DapperPocoInfo dpi = type.GetPocoInfo();  
                basicSql.FullInsertSql = this.GetInsertSql(dpi, dpi.TypeProperties);  
            }  
            return basicSql.FullInsertSql;  
        }  
  
        private string GetInsertSql(DapperPocoInfo dpi, IEnumerable<PropertyInfo> props)  
        {  
            StringBuilder tmp = new StringBuilder();  
            tmp.Append("INSERT INTO ");  
            tmp.AppendLine(dpi.TableName);  
            tmp.Append('(');  
  
            IEnumerable<PropertyInfo> valueProps = props;  
            if (dpi.IsUnWriteKey())  
            {  
                valueProps = this.GetExceptProps(props, dpi.KeyProperties);  
            }  
  
            this.AppendColumnList(tmp, valueProps, '\0');  
            tmp.Append(')');  
            tmp.AppendLine(" VALUES ");  
            tmp.Append('(');  
            this.AppendColumnList(tmp, valueProps, SqlParameterChar);  
            tmp.Append(')');  
  
            return tmp.ToString();  
        }  
        private void AppendColumnList(StringBuilder tmp, IEnumerable<PropertyInfo> valueProps, char addChar)  
        {  
            foreach (PropertyInfo p in valueProps)  
            {  
                tmp.Append(addChar);  
                tmp.Append(p.Name);  
                tmp.Append(',');  
            }  
            tmp.Remove(tmp.Length - 1, 1);  
        }  
        private IEnumerable<PropertyInfo> GetExceptProps(IEnumerable<PropertyInfo> props1, IEnumerable<PropertyInfo> props2)  
        {  
            //return props1.Except(props2, new EqualityCompareProperty()).ToArray();  
            IList<PropertyInfo> list = new List<PropertyInfo>();  
            foreach (PropertyInfo pi in props1)  
            {  
                string name = pi.Name.ToLower();  
                if (!props2.Any(p => p.Name.ToLower() == name))  
                {  
                    list.Add(pi);  
                }  
            }  
            return list;  
        }  
        private string GetUpdateSql(DapperPocoInfo dpi, IEnumerable<PropertyInfo> props)  
        {  
            StringBuilder tmp = new StringBuilder();  
            tmp.Append("UPDATE ");  
            tmp.AppendLine(dpi.TableName);  
            tmp.Append("SET ");  
            IEnumerable<PropertyInfo> valueProps = this.GetExceptProps(props, dpi.KeyProperties);  
            foreach (PropertyInfo p in valueProps)  
            {  
                tmp.Append(p.Name);  
                tmp.Append('=');  
                tmp.Append(SqlParameterChar);  
                tmp.Append(p.Name);  
                tmp.Append(',');  
            }  
            tmp.Remove(tmp.Length - 1, 1);  
            tmp.AppendLine();  
            this.AppendKeyParameter(tmp, dpi.KeyProperties);  
            return tmp.ToString();  
        }  
  
        public string GetFullUpdateByKeySql(Type type)  
        {  
            BasicSql basicSql = this.GetBasicSql(type);  
            if (string.IsNullOrEmpty(basicSql.FullUpdateByKeySql))  
            {  
                DapperPocoInfo dpi = type.GetPocoInfo();  
                basicSql.FullUpdateByKeySql = this.GetUpdateSql(dpi, dpi.TypeProperties);  
            }  
            return basicSql.FullUpdateByKeySql;  
        }  
  
        public string GetDeleteByKeySql(Type type)  
        {  
            BasicSql basicSql = this.GetBasicSql(type);  
            if (string.IsNullOrEmpty(basicSql.DeleteByKeySql))  
            {  
                DapperPocoInfo dpi = type.GetPocoInfo();  
                StringBuilder tmp = new StringBuilder();  
                tmp.Append("DELETE FROM ");  
                tmp.AppendLine(dpi.TableName);  
                this.AppendKeyParameter(tmp, dpi.KeyProperties);  
                basicSql.DeleteByKeySql = tmp.ToString();  
            }  
            return basicSql.DeleteByKeySql;  
        }  
  
        public bool Insert<T>(IDbConnection connection, object entity, IDbTransaction transaction = null, int? commandTimeout = null) where T : class  
        {  
            Type type = typeof(T);  
            string insertSql;  
            Type entityType = entity.GetType();  
            DapperPocoInfo dpi = type.GetPocoInfo();  
            if (entityType.IsAssignableFrom(type))  
            {  
                insertSql = this.GetFullInsertSql(type);  
            }  
            else  
            {  
                insertSql = this.GetInsertSql(dpi, entityType.GetProperties());  
            }  
  
            if (connection.Execute<T>(insertSql, entity, transaction, commandTimeout) > 0)  
            {  
                if (entityType.IsAssignableFrom(type) && dpi.IsUnWriteKey())  
                {  
                    PropertyInfo key = dpi.KeyProperties.First();  
                    if (key.PropertyType != typeof(Guid))  
                    {  
                        var idValue = this.GetLastInsertID(connection, dpi, transaction, commandTimeout);  
                        key.SetValue(entity, idValue, null);  
                    }  
                }  
                return true;  
            }  
            return false;  
        }  
  
        public bool UpdateByKey<T>(IDbConnection connection, object entity, IDbTransaction transaction = null, int? commandTimeout = null) where T : class  
        {  
            Type type = typeof(T);  
            string updateSql;  
            Type entityType = entity.GetType();  
            DapperPocoInfo dpi = type.GetPocoInfo();  
            if (entityType.IsAssignableFrom(type))  
            {  
                updateSql = this.GetFullUpdateByKeySql(type);  
            }  
            else  
            {  
                updateSql = this.GetUpdateSql(dpi, entityType.GetProperties());  
            }  
            return connection.Execute<T>(updateSql, entity, transaction, commandTimeout) > 0;  
        }  
  
        public bool DeleteByKey<T>(IDbConnection connection, object param, IDbTransaction transaction = null, int? commandTimeout = null) where T : class  
        {  
            string deleteSql = this.GetDeleteByKeySql(typeof(T));  
            return connection.Execute<T>(deleteSql, param, transaction: transaction, commandTimeout: commandTimeout) > 0;  
        }  
  
        public T QueryByKey<T>(IDbConnection connection, object param, IDbTransaction transaction = null, int? commandTimeout = null) where T : class  
        {  
            string querySql = this.GetFullQueryByKeySql(typeof(T));  
            return connection.Query<T>(querySql, param, transaction: transaction, commandTimeout: commandTimeout).FirstOrDefault();  
        }  
  
        private object GetLastInsertID(IDbConnection connection, DapperPocoInfo dpi, IDbTransaction transaction = null, int? commandTimeout = null)  
        {  
            var r = connection.Query("SELECT IDENT_CURRENT('" + dpi.TableName + "') ID", transaction: transaction, commandTimeout: commandTimeout);  
            return Convert.ChangeType(r.First().ID, dpi.KeyProperties.First().PropertyType);  
        }  
  
        public long GetLastInsertID<T>(IDbConnection connection)  
            where T : class  
        {  
            DapperPocoInfo dpi = typeof(T).GetPocoInfo();  
            return Convert.ToInt64(this.GetLastInsertID(connection, dpi));  
        }  
    }  
}  
 

原Dapper部分，在1965行开始做了些修改：

/* 
 License: http://www.apache.org/licenses/LICENSE-2.0  
 Home page: http://code.google.com/p/dapper-dot-net/ 
 
 Note: to build on C# 3.0 + .NET 3.5, include the CSHARP30 compiler symbol (and yes, 
 I know the difference between language and runtime versions; this is a compromise). 
 */  
  
using System;  
using System.Collections;  
using System.Collections.Generic;  
using System.ComponentModel;  
using System.Data;  
using System.Linq;  
using System.Reflection;  
using System.Reflection.Emit;  
using System.Text;  
using System.Threading;  
using System.Text.RegularExpressions;  
using System.Diagnostics;  
  
  
namespace Dapper  
{  
    /// <summary>  
    /// Dapper, a light weight object mapper for ADO.NET  
    /// </summary>  
    static partial class SqlMapper  
    {  
        /// <summary>  
        /// Implement this interface to pass an arbitrary db specific set of parameters to Dapper  
        /// </summary>  
        public partial interface IDynamicParameters  
        {  
            /// <summary>  
            /// Add all the parameters needed to the command just before it executes  
            /// </summary>  
            /// <param name="command">The raw command prior to execution</param>  
            /// <param name="identity">Information about the query</param>  
            void AddParameters(IDbCommand command, Identity identity);  
        }  
  
        /// <summary>  
        /// Implement this interface to pass an arbitrary db specific parameter to Dapper  
        /// </summary>  
        public interface ICustomQueryParameter  
        {  
            /// <summary>  
            /// Add the parameter needed to the command before it executes  
            /// </summary>  
            /// <param name="command">The raw command prior to execution</param>  
            /// <param name="name">Parameter name</param>  
            void AddParameter(IDbCommand command, string name);  
        }  
  
        /// <summary>  
        /// Implement this interface to change default mapping of reader columns to type memebers  
        /// </summary>  
        public interface ITypeMap  
        {  
            /// <summary>  
            /// Finds best constructor  
            /// </summary>  
            /// <param name="names">DataReader column names</param>  
            /// <param name="types">DataReader column types</param>  
            /// <returns>Matching constructor or default one</returns>  
            ConstructorInfo FindConstructor(string[] names, Type[] types);  
  
            /// <summary>  
            /// Gets mapping for constructor parameter  
            /// </summary>  
            /// <param name="constructor">Constructor to resolve</param>  
            /// <param name="columnName">DataReader column name</param>  
            /// <returns>Mapping implementation</returns>  
            IMemberMap GetConstructorParameter(ConstructorInfo constructor, string columnName);  
  
            /// <summary>  
            /// Gets member mapping for column  
            /// </summary>  
            /// <param name="columnName">DataReader column name</param>  
            /// <returns>Mapping implementation</returns>  
            IMemberMap GetMember(string columnName);  
        }  
  
        /// <summary>  
        /// Implements this interface to provide custom member mapping  
        /// </summary>  
        public interface IMemberMap  
        {  
            /// <summary>  
            /// Source DataReader column name  
            /// </summary>  
            string ColumnName { get; }  
  
            /// <summary>  
            ///  Target member type  
            /// </summary>  
            Type MemberType { get; }  
  
            /// <summary>  
            /// Target property  
            /// </summary>  
            PropertyInfo Property { get; }  
  
            /// <summary>  
            /// Target field  
            /// </summary>  
            FieldInfo Field { get; }  
  
            /// <summary>  
            /// Target constructor parameter  
            /// </summary>  
            ParameterInfo Parameter { get; }  
        }  
  
        static Link<Type, Action<IDbCommand, bool>> bindByNameCache;  
        static Action<IDbCommand, bool> GetBindByName(Type commandType)  
        {  
            if (commandType == null) return null; // GIGO  
            Action<IDbCommand, bool> action;  
            if (Link<Type, Action<IDbCommand, bool>>.TryGet(bindByNameCache, commandType, out action))  
            {  
                return action;  
            }  
            var prop = commandType.GetProperty("BindByName", BindingFlags.Public | BindingFlags.Instance);  
            action = null;  
            ParameterInfo[] indexers;  
            MethodInfo setter;  
            if (prop != null && prop.CanWrite && prop.PropertyType == typeof(bool)  
                && ((indexers = prop.GetIndexParameters()) == null || indexers.Length == 0)  
                && (setter = prop.GetSetMethod()) != null  
                )  
            {  
                var method = new DynamicMethod(commandType.Name + "_BindByName", null, new Type[] { typeof(IDbCommand), typeof(bool) });  
                var il = method.GetILGenerator();  
                il.Emit(OpCodes.Ldarg_0);  
                il.Emit(OpCodes.Castclass, commandType);  
                il.Emit(OpCodes.Ldarg_1);  
                il.EmitCall(OpCodes.Callvirt, setter, null);  
                il.Emit(OpCodes.Ret);  
                action = (Action<IDbCommand, bool>)method.CreateDelegate(typeof(Action<IDbCommand, bool>));  
            }  
            // cache it              
            Link<Type, Action<IDbCommand, bool>>.TryAdd(ref bindByNameCache, commandType, ref action);  
            return action;  
        }  
        /// <summary>  
        /// This is a micro-cache; suitable when the number of terms is controllable (a few hundred, for example),  
        /// and strictly append-only; you cannot change existing values. All key matches are on **REFERENCE**  
        /// equality. The type is fully thread-safe.  
        /// </summary>  
        partial class Link<TKey, TValue> where TKey : class  
        {  
            public static bool TryGet(Link<TKey, TValue> link, TKey key, out TValue value)  
            {  
                while (link != null)  
                {  
                    if ((object)key == (object)link.Key)  
                    {  
                        value = link.Value;  
                        return true;  
                    }  
                    link = link.Tail;  
                }  
                value = default(TValue);  
                return false;  
            }  
            public static bool TryAdd(ref Link<TKey, TValue> head, TKey key, ref TValue value)  
            {  
                bool tryAgain;  
                do  
                {  
                    var snapshot = Interlocked.CompareExchange(ref head, null, null);  
                    TValue found;  
                    if (TryGet(snapshot, key, out found))  
                    { // existing match; report the existing value instead  
                        value = found;  
                        return false;  
                    }  
                    var newNode = new Link<TKey, TValue>(key, value, snapshot);  
                    // did somebody move our cheese?  
                    tryAgain = Interlocked.CompareExchange(ref head, newNode, snapshot) != snapshot;  
                } while (tryAgain);  
                return true;  
            }  
            private Link(TKey key, TValue value, Link<TKey, TValue> tail)  
            {  
                Key = key;  
                Value = value;  
                Tail = tail;  
            }  
            public TKey Key { get; private set; }  
            public TValue Value { get; private set; }  
            public Link<TKey, TValue> Tail { get; private set; }  
        }  
        partial class CacheInfo  
        {  
            public DeserializerState Deserializer { get; set; }  
            public Func<IDataReader, object>[] OtherDeserializers { get; set; }  
            public Action<IDbCommand, object> ParamReader { get; set; }  
            private int hitCount;  
            public int GetHitCount() { return Interlocked.CompareExchange(ref hitCount, 0, 0); }  
            public void RecordHit() { Interlocked.Increment(ref hitCount); }  
        }  
        static int GetColumnHash(IDataReader reader)  
        {  
            unchecked  
            {  
                int colCount = reader.FieldCount, hash = colCount;  
                for (int i = 0; i < colCount; i++)  
                {   // binding code is only interested in names - not types  
                    object tmp = reader.GetName(i);  
                    hash = (hash * 31) + (tmp == null ? 0 : tmp.GetHashCode());  
                }  
                return hash;  
            }  
        }  
        struct DeserializerState  
        {  
            public readonly int Hash;  
            public readonly Func<IDataReader, object> Func;  
  
            public DeserializerState(int hash, Func<IDataReader, object> func)  
            {  
                Hash = hash;  
                Func = func;  
            }  
        }  
  
        /// <summary>  
        /// Called if the query cache is purged via PurgeQueryCache  
        /// </summary>  
        public static event EventHandler QueryCachePurged;  
        private static void OnQueryCachePurged()  
        {  
            var handler = QueryCachePurged;  
            if (handler != null) handler(null, EventArgs.Empty);  
        }  
#if CSHARP30  
        private static readonly Dictionary<Identity, CacheInfo> _queryCache = new Dictionary<Identity, CacheInfo>();  
        // note: conflicts between readers and writers are so short-lived that it isn't worth the overhead of  
        // ReaderWriterLockSlim etc; a simple lock is faster  
        private static void SetQueryCache(Identity key, CacheInfo value)  
        {  
            lock (_queryCache) { _queryCache[key] = value; }  
        }  
        private static bool TryGetQueryCache(Identity key, out CacheInfo value)  
        {  
            lock (_queryCache) { return _queryCache.TryGetValue(key, out value); }  
        }  
        private static void PurgeQueryCacheByType(Type type)  
        {  
            lock (_queryCache)  
            {  
                var toRemove = _queryCache.Keys.Where(id => id.type == type).ToArray();  
                foreach (var key in toRemove)  
                    _queryCache.Remove(key);  
            }  
        }  
        /// <summary>  
        /// Purge the query cache   
        /// </summary>  
        public static void PurgeQueryCache()  
        {  
            lock (_queryCache)  
            {  
                _queryCache.Clear();  
            }  
            OnQueryCachePurged();  
        }  
#else  
        static readonly System.Collections.Concurrent.ConcurrentDictionary<Identity, CacheInfo> _queryCache = new System.Collections.Concurrent.ConcurrentDictionary<Identity, CacheInfo>();  
        private static void SetQueryCache(Identity key, CacheInfo value)  
        {  
            if (Interlocked.Increment(ref collect) == COLLECT_PER_ITEMS)  
            {  
                CollectCacheGarbage();  
            }  
            _queryCache[key] = value;  
        }  
  
        private static void CollectCacheGarbage()  
        {  
            try  
            {  
                foreach (var pair in _queryCache)  
                {  
                    if (pair.Value.GetHitCount() <= COLLECT_HIT_COUNT_MIN)  
                    {  
                        CacheInfo cache;  
                        _queryCache.TryRemove(pair.Key, out cache);  
                    }  
                }  
            }  
  
            finally  
            {  
                Interlocked.Exchange(ref collect, 0);  
            }  
        }  
  
        private const int COLLECT_PER_ITEMS = 1000, COLLECT_HIT_COUNT_MIN = 0;  
        private static int collect;  
        private static bool TryGetQueryCache(Identity key, out CacheInfo value)  
        {  
            if (_queryCache.TryGetValue(key, out value))  
            {  
                value.RecordHit();  
                return true;  
            }  
            value = null;  
            return false;  
        }  
  
        /// <summary>  
        /// Purge the query cache   
        /// </summary>  
        public static void PurgeQueryCache()  
        {  
            _queryCache.Clear();  
            OnQueryCachePurged();  
        }  
  
        private static void PurgeQueryCacheByType(Type type)  
        {  
            foreach (var entry in _queryCache)  
            {  
                CacheInfo cache;  
                if (entry.Key.type == type)  
                    _queryCache.TryRemove(entry.Key, out cache);  
            }  
        }  
  
        /// <summary>  
        /// Return a count of all the cached queries by dapper  
        /// </summary>  
        /// <returns></returns>  
        public static int GetCachedSQLCount()  
        {  
            return _queryCache.Count;  
        }  
  
        /// <summary>  
        /// Return a list of all the queries cached by dapper  
        /// </summary>  
        /// <param name="ignoreHitCountAbove"></param>  
        /// <returns></returns>  
        public static IEnumerable<Tuple<string, string, int>> GetCachedSQL(int ignoreHitCountAbove = int.MaxValue)  
        {  
            var data = _queryCache.Select(pair => Tuple.Create(pair.Key.connectionString, pair.Key.sql, pair.Value.GetHitCount()));  
            if (ignoreHitCountAbove < int.MaxValue) data = data.Where(tuple => tuple.Item3 <= ignoreHitCountAbove);  
            return data;  
        }  
  
        /// <summary>  
        /// Deep diagnostics only: find any hash collisions in the cache  
        /// </summary>  
        /// <returns></returns>  
        public static IEnumerable<Tuple<int, int>> GetHashCollissions()  
        {  
            var counts = new Dictionary<int, int>();  
            foreach (var key in _queryCache.Keys)  
            {  
                int count;  
                if (!counts.TryGetValue(key.hashCode, out count))  
                {  
                    counts.Add(key.hashCode, 1);  
                }  
                else  
                {  
                    counts[key.hashCode] = count + 1;  
                }  
            }  
            return from pair in counts  
                   where pair.Value > 1  
                   select Tuple.Create(pair.Key, pair.Value);  
  
        }  
#endif  
  
  
        static readonly Dictionary<Type, DbType> typeMap;  
  
        static SqlMapper()  
        {  
            typeMap = new Dictionary<Type, DbType>();  
            typeMap[typeof(byte)] = DbType.Byte;  
            typeMap[typeof(sbyte)] = DbType.SByte;  
            typeMap[typeof(short)] = DbType.Int16;  
            typeMap[typeof(ushort)] = DbType.UInt16;  
            typeMap[typeof(int)] = DbType.Int32;  
            typeMap[typeof(uint)] = DbType.UInt32;  
            typeMap[typeof(long)] = DbType.Int64;  
            typeMap[typeof(ulong)] = DbType.UInt64;  
            typeMap[typeof(float)] = DbType.Single;  
            typeMap[typeof(double)] = DbType.Double;  
            typeMap[typeof(decimal)] = DbType.Decimal;  
            typeMap[typeof(bool)] = DbType.Boolean;  
            typeMap[typeof(string)] = DbType.String;  
            typeMap[typeof(char)] = DbType.StringFixedLength;  
            typeMap[typeof(Guid)] = DbType.Guid;  
            typeMap[typeof(DateTime)] = DbType.DateTime;  
            typeMap[typeof(DateTimeOffset)] = DbType.DateTimeOffset;  
            typeMap[typeof(TimeSpan)] = DbType.Time;  
            typeMap[typeof(byte[])] = DbType.Binary;  
            typeMap[typeof(byte?)] = DbType.Byte;  
            typeMap[typeof(sbyte?)] = DbType.SByte;  
            typeMap[typeof(short?)] = DbType.Int16;  
            typeMap[typeof(ushort?)] = DbType.UInt16;  
            typeMap[typeof(int?)] = DbType.Int32;  
            typeMap[typeof(uint?)] = DbType.UInt32;  
            typeMap[typeof(long?)] = DbType.Int64;  
            typeMap[typeof(ulong?)] = DbType.UInt64;  
            typeMap[typeof(float?)] = DbType.Single;  
            typeMap[typeof(double?)] = DbType.Double;  
            typeMap[typeof(decimal?)] = DbType.Decimal;  
            typeMap[typeof(bool?)] = DbType.Boolean;  
            typeMap[typeof(char?)] = DbType.StringFixedLength;  
            typeMap[typeof(Guid?)] = DbType.Guid;  
            typeMap[typeof(DateTime?)] = DbType.DateTime;  
            typeMap[typeof(DateTimeOffset?)] = DbType.DateTimeOffset;  
            typeMap[typeof(TimeSpan?)] = DbType.Time;  
            typeMap[typeof(Object)] = DbType.Object;  
        }  
        /// <summary>  
        /// Configire the specified type to be mapped to a given db-type  
        /// </summary>  
        public static void AddTypeMap(Type type, DbType dbType)  
        {  
            typeMap[type] = dbType;  
        }  
  
        internal const string LinqBinary = "System.Data.Linq.Binary";  
        internal static DbType LookupDbType(Type type, string name)  
        {  
            DbType dbType;  
            var nullUnderlyingType = Nullable.GetUnderlyingType(type);  
            if (nullUnderlyingType != null) type = nullUnderlyingType;  
            if (type.IsEnum && !typeMap.ContainsKey(type))  
            {  
                type = Enum.GetUnderlyingType(type);  
            }  
            if (typeMap.TryGetValue(type, out dbType))  
            {  
                return dbType;  
            }  
            if (type.FullName == LinqBinary)  
            {  
                return DbType.Binary;  
            }  
            if (typeof(IEnumerable).IsAssignableFrom(type))  
            {  
                return DynamicParameters.EnumerableMultiParameter;  
            }  
  
  
            throw new NotSupportedException(string.Format("The member {0} of type {1} cannot be used as a parameter value", name, type));  
        }  
  
  
        /// <summary>  
        /// Identity of a cached query in Dapper, used for extensability  
        /// </summary>  
        public partial class Identity : IEquatable<Identity>  
        {  
            internal Identity ForGrid(Type primaryType, int gridIndex)  
            {  
                return new Identity(sql, commandType, connectionString, primaryType, parametersType, null, gridIndex);  
            }  
  
            internal Identity ForGrid(Type primaryType, Type[] otherTypes, int gridIndex)  
            {  
                return new Identity(sql, commandType, connectionString, primaryType, parametersType, otherTypes, gridIndex);  
            }  
            /// <summary>  
            /// Create an identity for use with DynamicParameters, internal use only  
            /// </summary>  
            /// <param name="type"></param>  
            /// <returns></returns>  
            public Identity ForDynamicParameters(Type type)  
            {  
                return new Identity(sql, commandType, connectionString, this.type, type, null, -1);  
            }  
  
            internal Identity(string sql, CommandType? commandType, IDbConnection connection, Type type, Type parametersType, Type[] otherTypes)  
                : this(sql, commandType, connection.ConnectionString, type, parametersType, otherTypes, 0)  
            { }  
            private Identity(string sql, CommandType? commandType, string connectionString, Type type, Type parametersType, Type[] otherTypes, int gridIndex)  
            {  
                this.sql = sql;  
                this.commandType = commandType;  
                this.connectionString = connectionString;  
                this.type = type;  
                this.parametersType = parametersType;  
                this.gridIndex = gridIndex;  
                unchecked  
                {  
                    hashCode = 17; // we *know* we are using this in a dictionary, so pre-compute this  
                    hashCode = hashCode * 23 + commandType.GetHashCode();  
                    hashCode = hashCode * 23 + gridIndex.GetHashCode();  
                    hashCode = hashCode * 23 + (sql == null ? 0 : sql.GetHashCode());  
                    hashCode = hashCode * 23 + (type == null ? 0 : type.GetHashCode());  
                    if (otherTypes != null)  
                    {  
                        foreach (var t in otherTypes)  
                        {  
                            hashCode = hashCode * 23 + (t == null ? 0 : t.GetHashCode());  
                        }  
                    }  
                    hashCode = hashCode * 23 + (connectionString == null ? 0 : SqlMapper.connectionStringComparer.GetHashCode(connectionString));  
                    hashCode = hashCode * 23 + (parametersType == null ? 0 : parametersType.GetHashCode());  
                }  
            }  
  
            /// <summary>  
            ///   
            /// </summary>  
            /// <param name="obj"></param>  
            /// <returns></returns>  
            public override bool Equals(object obj)  
            {  
                return Equals(obj as Identity);  
            }  
            /// <summary>  
            /// The sql  
            /// </summary>  
            public readonly string sql;  
            /// <summary>  
            /// The command type   
            /// </summary>  
            public readonly CommandType? commandType;  
  
            /// <summary>  
            ///   
            /// </summary>  
            public readonly int hashCode, gridIndex;  
            /// <summary>  
            ///   
            /// </summary>  
            public readonly Type type;  
            /// <summary>  
            ///   
            /// </summary>  
            public readonly string connectionString;  
            /// <summary>  
            ///   
            /// </summary>  
            public readonly Type parametersType;  
            /// <summary>  
            ///   
            /// </summary>  
            /// <returns></returns>  
            public override int GetHashCode()  
            {  
                return hashCode;  
            }  
            /// <summary>  
            /// Compare 2 Identity objects  
            /// </summary>  
            /// <param name="other"></param>  
            /// <returns></returns>  
            public bool Equals(Identity other)  
            {  
                return  
                    other != null &&  
                    gridIndex == other.gridIndex &&  
                    type == other.type &&  
                    sql == other.sql &&  
                    commandType == other.commandType &&  
                    SqlMapper.connectionStringComparer.Equals(connectionString, other.connectionString) &&  
                    parametersType == other.parametersType;  
            }  
        }  
 
#if CSHARP30  
        /// <summary>  
        /// Execute parameterized SQL    
        /// </summary>  
        /// <returns>Number of rows affected</returns>  
        public static int Execute(this IDbConnection cnn, string sql, object param)  
        {  
            return Execute(cnn, sql, param, null, null, null);  
        }  
  
        /// <summary>  
        /// Execute parameterized SQL  
        /// </summary>  
        /// <returns>Number of rows affected</returns>  
        public static int Execute(this IDbConnection cnn, string sql, object param, IDbTransaction transaction)  
        {  
            return Execute(cnn, sql, param, transaction, null, null);  
        }  
  
        /// <summary>  
        /// Execute parameterized SQL  
        /// </summary>  
        /// <returns>Number of rows affected</returns>  
        public static int Execute(this IDbConnection cnn, string sql, object param, CommandType commandType)  
        {  
            return Execute(cnn, sql, param, null, null, commandType);  
        }  
  
        /// <summary>  
        /// Execute parameterized SQL  
        /// </summary>  
        /// <returns>Number of rows affected</returns>  
        public static int Execute(this IDbConnection cnn, string sql, object param, IDbTransaction transaction, CommandType commandType)  
        {  
            return Execute(cnn, sql, param, transaction, null, commandType);  
        }  
  
        /// <summary>  
        /// Executes a query, returning the data typed as per T  
        /// </summary>  
        /// <returns>A sequence of data of the supplied type; if a basic type (int, string, etc) is queried then the data from the first column in assumed, otherwise an instance is  
        /// created per row, and a direct column-name===member-name mapping is assumed (case insensitive).  
        /// </returns>  
        public static IEnumerable<T> Query<T>(this IDbConnection cnn, string sql, object param)  
        {  
            return Query<T>(cnn, sql, param, null, true, null, null);  
        }  
  
        /// <summary>  
        /// Executes a query, returning the data typed as per T  
        /// </summary>  
        /// <returns>A sequence of data of the supplied type; if a basic type (int, string, etc) is queried then the data from the first column in assumed, otherwise an instance is  
        /// created per row, and a direct column-name===member-name mapping is assumed (case insensitive).  
        /// </returns>  
        public static IEnumerable<T> Query<T>(this IDbConnection cnn, string sql, object param, IDbTransaction transaction)  
        {  
            return Query<T>(cnn, sql, param, transaction, true, null, null);  
        }  
  
        /// <summary>  
        /// Executes a query, returning the data typed as per T  
        /// </summary>  
        /// <returns>A sequence of data of the supplied type; if a basic type (int, string, etc) is queried then the data from the first column in assumed, otherwise an instance is  
        /// created per row, and a direct column-name===member-name mapping is assumed (case insensitive).  
        /// </returns>  
        public static IEnumerable<T> Query<T>(this IDbConnection cnn, string sql, object param, CommandType commandType)  
        {  
            return Query<T>(cnn, sql, param, null, true, null, commandType);  
        }  
  
        /// <summary>  
        /// Executes a query, returning the data typed as per T  
        /// </summary>  
        /// <returns>A sequence of data of the supplied type; if a basic type (int, string, etc) is queried then the data from the first column in assumed, otherwise an instance is  
        /// created per row, and a direct column-name===member-name mapping is assumed (case insensitive).  
        /// </returns>  
        public static IEnumerable<T> Query<T>(this IDbConnection cnn, string sql, object param, IDbTransaction transaction, CommandType commandType)  
        {  
            return Query<T>(cnn, sql, param, transaction, true, null, commandType);  
        }  
  
        /// <summary>  
        /// Execute a command that returns multiple result sets, and access each in turn  
        /// </summary>  
        public static GridReader QueryMultiple(this IDbConnection cnn, string sql, object param, IDbTransaction transaction)  
        {  
            return QueryMultiple(cnn, sql, param, transaction, null, null);  
        }  
  
        /// <summary>  
        /// Execute a command that returns multiple result sets, and access each in turn  
        /// </summary>  
        public static GridReader QueryMultiple(this IDbConnection cnn, string sql, object param, CommandType commandType)  
        {  
            return QueryMultiple(cnn, sql, param, null, null, commandType);  
        }  
  
        /// <summary>  
        /// Execute a command that returns multiple result sets, and access each in turn  
        /// </summary>  
        public static GridReader QueryMultiple(this IDbConnection cnn, string sql, object param, IDbTransaction transaction, CommandType commandType)  
        {  
            return QueryMultiple(cnn, sql, param, transaction, null, commandType);  
        }  
#endif  
  
        private static int Execute(  
#if CSHARP30  
this IDbConnection cnn, string sql,Type type, object param, IDbTransaction transaction, int? commandTimeout, CommandType? commandType  
#else  
this IDbConnection cnn, string sql, Type type, dynamic param = null, IDbTransaction transaction = null, int? commandTimeout = null, CommandType? commandType = null  
#endif  
)  
        {  
            IEnumerable multiExec = (object)param as IEnumerable;  
            Identity identity;  
            CacheInfo info = null;  
            if (multiExec != null && !(multiExec is string))  
            {  
                bool isFirst = true;  
                int total = 0;  
                using (var cmd = SetupCommand(cnn, transaction, sql, null, null, commandTimeout, commandType))  
                {  
  
                    string masterSql = null;  
                    foreach (var obj in multiExec)  
                    {  
                        if (isFirst)  
                        {  
                            masterSql = cmd.CommandText;  
                            isFirst = false;  
                            identity = new Identity(sql, cmd.CommandType, cnn, type, obj.GetType(), null);  
                            info = GetCacheInfo(identity);  
                        }  
                        else  
                        {  
                            cmd.CommandText = masterSql; // because we do magic replaces on "in" etc  
                            cmd.Parameters.Clear(); // current code is Add-tastic  
                        }  
                        info.ParamReader(cmd, obj);  
                        total += cmd.ExecuteNonQuery();  
                    }  
                }  
                return total;  
            }  
  
            // nice and simple  
            if ((object)param != null)  
            {  
                identity = new Identity(sql, commandType, cnn, type, (object)param == null ? null : ((object)param).GetType(), null);  
                info = GetCacheInfo(identity);  
            }  
            return ExecuteCommand(cnn, transaction, sql, (object)param == null ? null : info.ParamReader, (object)param, commandTimeout, commandType);  
        }  
  
        /// <summary>  
        /// Execute parameterized SQL    
        /// </summary>  
        /// <returns>Number of rows affected</returns>  
        public static int Execute<T>(  
#if CSHARP30  
this IDbConnection cnn, string sql, object param, IDbTransaction transaction, int? commandTimeout, CommandType? commandType  
#else  
this IDbConnection cnn, string sql, dynamic param = null, IDbTransaction transaction = null, int? commandTimeout = null, CommandType? commandType = null  
#endif  
)  
            where T : class  
        {  
            return Execute(cnn, sql, typeof(T), param, transaction, commandTimeout, commandType);  
        }  
        /// <summary>  
        /// Execute parameterized SQL    
        /// </summary>  
        /// <returns>Number of rows affected</returns>  
        public static int Execute(  
#if CSHARP30  
this IDbConnection cnn, string sql, object param, IDbTransaction transaction, int? commandTimeout, CommandType? commandType  
#else  
this IDbConnection cnn, string sql, dynamic param = null, IDbTransaction transaction = null, int? commandTimeout = null, CommandType? commandType = null  
#endif  
)  
        {  
            return Execute(cnn, sql, null, param, transaction, commandTimeout, commandType);  
        }  
 
#if !CSHARP30  
        /// <summary>  
        /// Return a list of dynamic objects, reader is closed after the call  
        /// </summary>  
        public static IEnumerable<dynamic> Query(this IDbConnection cnn, string sql, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, int? commandTimeout = null, CommandType? commandType = null)  
        {  
            return Query<DapperRow>(cnn, sql, param as object, transaction, buffered, commandTimeout, commandType);  
        }  
#else  
        /// <summary>  
        /// Return a list of dynamic objects, reader is closed after the call  
        /// </summary>  
        public static IEnumerable<IDictionary<string, object>> Query(this IDbConnection cnn, string sql, object param)  
        {  
            return Query(cnn, sql, param, null, true, null, null);  
        }  
  
        /// <summary>  
        /// Return a list of dynamic objects, reader is closed after the call  
        /// </summary>  
        public static IEnumerable<IDictionary<string, object>> Query(this IDbConnection cnn, string sql, object param, IDbTransaction transaction)  
        {  
            return Query(cnn, sql, param, transaction, true, null, null);  
        }  
  
        /// <summary>  
        /// Return a list of dynamic objects, reader is closed after the call  
        /// </summary>  
        public static IEnumerable<IDictionary<string, object>> Query(this IDbConnection cnn, string sql, object param, CommandType? commandType)  
        {  
            return Query(cnn, sql, param, null, true, null, commandType);  
        }  
  
        /// <summary>  
        /// Return a list of dynamic objects, reader is closed after the call  
        /// </summary>  
        public static IEnumerable<IDictionary<string, object>> Query(this IDbConnection cnn, string sql, object param, IDbTransaction transaction, CommandType? commandType)  
        {  
            return Query(cnn, sql, param, transaction, true, null, commandType);  
        }  
  
        /// <summary>  
        /// Return a list of dynamic objects, reader is closed after the call  
        /// </summary>  
        public static IEnumerable<IDictionary<string, object>> Query(this IDbConnection cnn, string sql, object param, IDbTransaction transaction, bool buffered, int? commandTimeout, CommandType? commandType)  
        {  
            return Query<IDictionary<string, object>>(cnn, sql, param, transaction, buffered, commandTimeout, commandType);  
        }  
#endif  
  
        /// <summary>  
        /// Executes a query, returning the data typed as per T  
        /// </summary>  
        /// <remarks>the dynamic param may seem a bit odd, but this works around a major usability issue in vs, if it is Object vs completion gets annoying. Eg type new [space] get new object</remarks>  
        /// <returns>A sequence of data of the supplied type; if a basic type (int, string, etc) is queried then the data from the first column in assumed, otherwise an instance is  
        /// created per row, and a direct column-name===member-name mapping is assumed (case insensitive).  
        /// </returns>  
        public static IEnumerable<T> Query<T>(  
#if CSHARP30  
this IDbConnection cnn, string sql, object param, IDbTransaction transaction, bool buffered, int? commandTimeout, CommandType? commandType  
#else  
this IDbConnection cnn, string sql, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, int? commandTimeout = null, CommandType? commandType = null  
#endif  
)  
        {  
            var data = QueryInternal<T>(cnn, sql, param as object, transaction, commandTimeout, commandType);  
            return buffered ? data.ToList() : data;  
        }  
  
        /// <summary>  
        /// Execute a command that returns multiple result sets, and access each in turn  
        /// </summary>  
        public static GridReader QueryMultiple(  
#if CSHARP30  
this IDbConnection cnn, string sql, object param, IDbTransaction transaction, int? commandTimeout, CommandType? commandType  
#else  
            this IDbConnection cnn, string sql, dynamic param = null, IDbTransaction transaction = null, int? commandTimeout = null, CommandType? commandType = null  
#endif  
)  
        {  
            Identity identity = new Identity(sql, commandType, cnn, typeof(GridReader), (object)param == null ? null : ((object)param).GetType(), null);  
            CacheInfo info = GetCacheInfo(identity);  
  
            IDbCommand cmd = null;  
            IDataReader reader = null;  
            bool wasClosed = cnn.State == ConnectionState.Closed;  
            try  
            {  
                if (wasClosed) cnn.Open();  
                cmd = SetupCommand(cnn, transaction, sql, info.ParamReader, (object)param, commandTimeout, commandType);  
                reader = cmd.ExecuteReader(wasClosed ? CommandBehavior.CloseConnection : CommandBehavior.Default);  
  
                var result = new GridReader(cmd, reader, identity);  
                wasClosed = false; // *if* the connection was closed and we got this far, then we now have a reader  
                // with the CloseConnection flag, so the reader will deal with the connection; we  
                // still need something in the "finally" to ensure that broken SQL still results  
                // in the connection closing itself  
                return result;  
            }  
            catch  
            {  
                if (reader != null)  
                {  
                    if (!reader.IsClosed) try { cmd.Cancel(); }  
                        catch { /* don't spoil the existing exception */ }  
                    reader.Dispose();  
                }  
                if (cmd != null) cmd.Dispose();  
                if (wasClosed) cnn.Close();  
                throw;  
            }  
        }  
  
        /// <summary>  
        /// Return a typed list of objects, reader is closed after the call  
        /// </summary>  
        private static IEnumerable<T> QueryInternal<T>(this IDbConnection cnn, string sql, object param, IDbTransaction transaction, int? commandTimeout, CommandType? commandType)  
        {  
            var identity = new Identity(sql, commandType, cnn, typeof(T), param == null ? null : param.GetType(), null);  
            var info = GetCacheInfo(identity);  
  
            IDbCommand cmd = null;  
            IDataReader reader = null;  
  
            bool wasClosed = cnn.State == ConnectionState.Closed;  
            try  
            {  
                cmd = SetupCommand(cnn, transaction, sql, info.ParamReader, param, commandTimeout, commandType);  
  
                if (wasClosed) cnn.Open();  
                reader = cmd.ExecuteReader(wasClosed ? CommandBehavior.CloseConnection : CommandBehavior.Default);  
                wasClosed = false; // *if* the connection was closed and we got this far, then we now have a reader  
                // with the CloseConnection flag, so the reader will deal with the connection; we  
                // still need something in the "finally" to ensure that broken SQL still results  
                // in the connection closing itself  
                var tuple = info.Deserializer;  
                int hash = GetColumnHash(reader);  
                if (tuple.Func == null || tuple.Hash != hash)  
                {  
                    tuple = info.Deserializer = new DeserializerState(hash, GetDeserializer(typeof(T), reader, 0, -1, false));  
                    SetQueryCache(identity, info);  
                }  
  
                var func = tuple.Func;  
  
                while (reader.Read())  
                {  
                    yield return (T)func(reader);  
                }  
                // happy path; close the reader cleanly - no  
                // need for "Cancel" etc  
                reader.Dispose();  
                reader = null;  
            }  
            finally  
            {  
                if (reader != null)  
                {  
                    if (!reader.IsClosed) try { cmd.Cancel(); }  
                        catch { /* don't spoil the existing exception */ }  
                    reader.Dispose();  
                }  
                if (wasClosed) cnn.Close();  
                if (cmd != null) cmd.Dispose();  
            }  
        }  
  
        /// <summary>  
        /// Maps a query to objects  
        /// </summary>  
        /// <typeparam name="TFirst">The first type in the recordset</typeparam>  
        /// <typeparam name="TSecond">The second type in the recordset</typeparam>  
        /// <typeparam name="TReturn">The return type</typeparam>  
        /// <param name="cnn"></param>  
        /// <param name="sql"></param>  
        /// <param name="map"></param>  
        /// <param name="param"></param>  
        /// <param name="transaction"></param>  
        /// <param name="buffered"></param>  
        /// <param name="splitOn">The Field we should split and read the second object from (default: id)</param>  
        /// <param name="commandTimeout">Number of seconds before command execution timeout</param>  
        /// <param name="commandType">Is it a stored proc or a batch?</param>  
        /// <returns></returns>  
        public static IEnumerable<TReturn> Query<TFirst, TSecond, TReturn>(  
#if CSHARP30  
this IDbConnection cnn, string sql, Func<TFirst, TSecond, TReturn> map, object param, IDbTransaction transaction, bool buffered, string splitOn, int? commandTimeout, CommandType? commandType  
#else  
this IDbConnection cnn, string sql, Func<TFirst, TSecond, TReturn> map, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, string splitOn = "Id", int? commandTimeout = null, CommandType? commandType = null  
#endif  
)  
        {  
            return MultiMap<TFirst, TSecond, DontMap, DontMap, DontMap, DontMap, DontMap, TReturn>(cnn, sql, map, param as object, transaction, buffered, splitOn, commandTimeout, commandType);  
        }  
  
        /// <summary>  
        /// Maps a query to objects  
        /// </summary>  
        /// <typeparam name="TFirst"></typeparam>  
        /// <typeparam name="TSecond"></typeparam>  
        /// <typeparam name="TThird"></typeparam>  
        /// <typeparam name="TReturn"></typeparam>  
        /// <param name="cnn"></param>  
        /// <param name="sql"></param>  
        /// <param name="map"></param>  
        /// <param name="param"></param>  
        /// <param name="transaction"></param>  
        /// <param name="buffered"></param>  
        /// <param name="splitOn">The Field we should split and read the second object from (default: id)</param>  
        /// <param name="commandTimeout">Number of seconds before command execution timeout</param>  
        /// <param name="commandType"></param>  
        /// <returns></returns>  
        public static IEnumerable<TReturn> Query<TFirst, TSecond, TThird, TReturn>(  
#if CSHARP30  
this IDbConnection cnn, string sql, Func<TFirst, TSecond, TThird, TReturn> map, object param, IDbTransaction transaction, bool buffered, string splitOn, int? commandTimeout, CommandType? commandType  
#else  
this IDbConnection cnn, string sql, Func<TFirst, TSecond, TThird, TReturn> map, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, string splitOn = "Id", int? commandTimeout = null, CommandType? commandType = null  
#endif  
)  
        {  
            return MultiMap<TFirst, TSecond, TThird, DontMap, DontMap, DontMap, DontMap, TReturn>(cnn, sql, map, param as object, transaction, buffered, splitOn, commandTimeout, commandType);  
        }  
  
        /// <summary>  
        /// Perform a multi mapping query with 4 input parameters  
        /// </summary>  
        /// <typeparam name="TFirst"></typeparam>  
        /// <typeparam name="TSecond"></typeparam>  
        /// <typeparam name="TThird"></typeparam>  
        /// <typeparam name="TFourth"></typeparam>  
        /// <typeparam name="TReturn"></typeparam>  
        /// <param name="cnn"></param>  
        /// <param name="sql"></param>  
        /// <param name="map"></param>  
        /// <param name="param"></param>  
        /// <param name="transaction"></param>  
        /// <param name="buffered"></param>  
        /// <param name="splitOn"></param>  
        /// <param name="commandTimeout"></param>  
        /// <param name="commandType"></param>  
        /// <returns></returns>  
        public static IEnumerable<TReturn> Query<TFirst, TSecond, TThird, TFourth, TReturn>(  
#if CSHARP30  
this IDbConnection cnn, string sql, Func<TFirst, TSecond, TThird, TFourth, TReturn> map, object param, IDbTransaction transaction, bool buffered, string splitOn, int? commandTimeout, CommandType? commandType  
#else  
this IDbConnection cnn, string sql, Func<TFirst, TSecond, TThird, TFourth, TReturn> map, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, string splitOn = "Id", int? commandTimeout = null, CommandType? commandType = null  
#endif  
)  
        {  
            return MultiMap<TFirst, TSecond, TThird, TFourth, DontMap, DontMap, DontMap, TReturn>(cnn, sql, map, param as object, transaction, buffered, splitOn, commandTimeout, commandType);  
        }  
 
#if !CSHARP30  
        /// <summary>  
        /// Perform a multi mapping query with 5 input parameters  
        /// </summary>  
        /// <typeparam name="TFirst"></typeparam>  
        /// <typeparam name="TSecond"></typeparam>  
        /// <typeparam name="TThird"></typeparam>  
        /// <typeparam name="TFourth"></typeparam>  
        /// <typeparam name="TFifth"></typeparam>  
        /// <typeparam name="TReturn"></typeparam>  
        /// <param name="cnn"></param>  
        /// <param name="sql"></param>  
        /// <param name="map"></param>  
        /// <param name="param"></param>  
        /// <param name="transaction"></param>  
        /// <param name="buffered"></param>  
        /// <param name="splitOn"></param>  
        /// <param name="commandTimeout"></param>  
        /// <param name="commandType"></param>  
        /// <returns></returns>  
        public static IEnumerable<TReturn> Query<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(  
            this IDbConnection cnn, string sql, Func<TFirst, TSecond, TThird, TFourth, TFifth, TReturn> map, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, string splitOn = "Id", int? commandTimeout = null, CommandType? commandType = null  
)  
        {  
            return MultiMap<TFirst, TSecond, TThird, TFourth, TFifth, DontMap, DontMap, TReturn>(cnn, sql, map, param as object, transaction, buffered, splitOn, commandTimeout, commandType);  
        }  
  
        /// <summary>  
        /// Perform a multi mapping query with 6 input parameters  
        /// </summary>  
        /// <typeparam name="TFirst"></typeparam>  
        /// <typeparam name="TSecond"></typeparam>  
        /// <typeparam name="TThird"></typeparam>  
        /// <typeparam name="TFourth"></typeparam>  
        /// <typeparam name="TFifth"></typeparam>  
        /// <typeparam name="TSixth"></typeparam>  
        /// <typeparam name="TReturn"></typeparam>  
        /// <param name="cnn"></param>  
        /// <param name="sql"></param>  
        /// <param name="map"></param>  
        /// <param name="param"></param>  
        /// <param name="transaction"></param>  
        /// <param name="buffered"></param>  
        /// <param name="splitOn"></param>  
        /// <param name="commandTimeout"></param>  
        /// <param name="commandType"></param>  
        /// <returns></returns>  
        public static IEnumerable<TReturn> Query<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TReturn>(  
            this IDbConnection cnn, string sql, Func<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TReturn> map, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, string splitOn = "Id", int? commandTimeout = null, CommandType? commandType = null  
)  
        {  
            return MultiMap<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, DontMap, TReturn>(cnn, sql, map, param as object, transaction, buffered, splitOn, commandTimeout, commandType);  
        }  
  
  
        /// <summary>  
        /// Perform a multi mapping query with 7 input parameters  
        /// </summary>  
        /// <typeparam name="TFirst"></typeparam>  
        /// <typeparam name="TSecond"></typeparam>  
        /// <typeparam name="TThird"></typeparam>  
        /// <typeparam name="TFourth"></typeparam>  
        /// <typeparam name="TFifth"></typeparam>  
        /// <typeparam name="TSixth"></typeparam>  
        /// <typeparam name="TSeventh"></typeparam>  
        /// <typeparam name="TReturn"></typeparam>  
        /// <param name="cnn"></param>  
        /// <param name="sql"></param>  
        /// <param name="map"></param>  
        /// <param name="param"></param>  
        /// <param name="transaction"></param>  
        /// <param name="buffered"></param>  
        /// <param name="splitOn"></param>  
        /// <param name="commandTimeout"></param>  
        /// <param name="commandType"></param>  
        /// <returns></returns>  
        public static IEnumerable<TReturn> Query<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn>(this IDbConnection cnn, string sql, Func<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn> map, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, string splitOn = "Id", int? commandTimeout = null, CommandType? commandType = null)  
        {  
            return MultiMap<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn>(cnn, sql, map, param as object, transaction, buffered, splitOn, commandTimeout, commandType);  
        }  
#endif  
        partial class DontMap { }  
        static IEnumerable<TReturn> MultiMap<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn>(  
            this IDbConnection cnn, string sql, object map, object param, IDbTransaction transaction, bool buffered, string splitOn, int? commandTimeout, CommandType? commandType)  
        {  
            var results = MultiMapImpl<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn>(cnn, sql, map, param, transaction, splitOn, commandTimeout, commandType, null, null);  
            return buffered ? results.ToList() : results;  
        }  
  
  
        static IEnumerable<TReturn> MultiMapImpl<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn>(this IDbConnection cnn, string sql, object map, object param, IDbTransaction transaction, string splitOn, int? commandTimeout, CommandType? commandType, IDataReader reader, Identity identity)  
        {  
            identity = identity ?? new Identity(sql, commandType, cnn, typeof(TFirst), (object)param == null ? null : ((object)param).GetType(), new[] { typeof(TFirst), typeof(TSecond), typeof(TThird), typeof(TFourth), typeof(TFifth), typeof(TSixth), typeof(TSeventh) });  
            CacheInfo cinfo = GetCacheInfo(identity);  
  
            IDbCommand ownedCommand = null;  
            IDataReader ownedReader = null;  
  
            bool wasClosed = cnn != null && cnn.State == ConnectionState.Closed;  
            try  
            {  
                if (reader == null)  
                {  
                    ownedCommand = SetupCommand(cnn, transaction, sql, cinfo.ParamReader, (object)param, commandTimeout, commandType);  
                    if (wasClosed) cnn.Open();  
                    ownedReader = ownedCommand.ExecuteReader();  
                    reader = ownedReader;  
                }  
                DeserializerState deserializer = default(DeserializerState);  
                Func<IDataReader, object>[] otherDeserializers = null;  
  
                int hash = GetColumnHash(reader);  
                if ((deserializer = cinfo.Deserializer).Func == null || (otherDeserializers = cinfo.OtherDeserializers) == null || hash != deserializer.Hash)  
                {  
                    var deserializers = GenerateDeserializers(new Type[] { typeof(TFirst), typeof(TSecond), typeof(TThird), typeof(TFourth), typeof(TFifth), typeof(TSixth), typeof(TSeventh) }, splitOn, reader);  
                    deserializer = cinfo.Deserializer = new DeserializerState(hash, deserializers[0]);  
                    otherDeserializers = cinfo.OtherDeserializers = deserializers.Skip(1).ToArray();  
                    SetQueryCache(identity, cinfo);  
                }  
  
                Func<IDataReader, TReturn> mapIt = GenerateMapper<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn>(deserializer.Func, otherDeserializers, map);  
  
                if (mapIt != null)  
                {  
                    while (reader.Read())  
                    {  
                        yield return mapIt(reader);  
                    }  
                }  
            }  
            finally  
            {  
                try  
                {  
                    if (ownedReader != null)  
                    {  
                        ownedReader.Dispose();  
                    }  
                }  
                finally  
                {  
                    if (ownedCommand != null)  
                    {  
                        ownedCommand.Dispose();  
                    }  
                    if (wasClosed) cnn.Close();  
                }  
            }  
        }  
  
        private static Func<IDataReader, TReturn> GenerateMapper<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn>(Func<IDataReader, object> deserializer, Func<IDataReader, object>[] otherDeserializers, object map)  
        {  
            switch (otherDeserializers.Length)  
            {  
                case 1:  
                    return r => ((Func<TFirst, TSecond, TReturn>)map)((TFirst)deserializer(r), (TSecond)otherDeserializers[0](r));  
                case 2:  
                    return r => ((Func<TFirst, TSecond, TThird, TReturn>)map)((TFirst)deserializer(r), (TSecond)otherDeserializers[0](r), (TThird)otherDeserializers[1](r));  
                case 3:  
                    return r => ((Func<TFirst, TSecond, TThird, TFourth, TReturn>)map)((TFirst)deserializer(r), (TSecond)otherDeserializers[0](r), (TThird)otherDeserializers[1](r), (TFourth)otherDeserializers[2](r));  
#if !CSHARP30  
                case 4:  
                    return r => ((Func<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>)map)((TFirst)deserializer(r), (TSecond)otherDeserializers[0](r), (TThird)otherDeserializers[1](r), (TFourth)otherDeserializers[2](r), (TFifth)otherDeserializers[3](r));  
                case 5:  
                    return r => ((Func<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TReturn>)map)((TFirst)deserializer(r), (TSecond)otherDeserializers[0](r), (TThird)otherDeserializers[1](r), (TFourth)otherDeserializers[2](r), (TFifth)otherDeserializers[3](r), (TSixth)otherDeserializers[4](r));  
                case 6:  
                    return r => ((Func<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn>)map)((TFirst)deserializer(r), (TSecond)otherDeserializers[0](r), (TThird)otherDeserializers[1](r), (TFourth)otherDeserializers[2](r), (TFifth)otherDeserializers[3](r), (TSixth)otherDeserializers[4](r), (TSeventh)otherDeserializers[5](r));  
#endif  
                default:  
                    throw new NotSupportedException();  
            }  
        }  
  
        private static Func<IDataReader, object>[] GenerateDeserializers(Type[] types, string splitOn, IDataReader reader)  
        {  
            int current = 0;  
            var splits = splitOn.Split(',').ToArray();  
            var splitIndex = 0;  
  
            Func<Type, int> nextSplit = type =>  
            {  
                var currentSplit = splits[splitIndex].Trim();  
                if (splits.Length > splitIndex + 1)  
                {  
                    splitIndex++;  
                }  
  
                bool skipFirst = false;  
                int startingPos = current + 1;  
                // if our current type has the split, skip the first time you see it.   
                if (type != typeof(Object))  
                {  
                    var props = DefaultTypeMap.GetSettableProps(type);  
                    var fields = DefaultTypeMap.GetSettableFields(type);  
  
                    foreach (var name in props.Select(p => p.Name).Concat(fields.Select(f => f.Name)))  
                    {  
                        if (string.Equals(name, currentSplit, StringComparison.OrdinalIgnoreCase))  
                        {  
                            skipFirst = true;  
                            startingPos = current;  
                            break;  
                        }  
                    }  
  
                }  
  
                int pos;  
                for (pos = startingPos; pos < reader.FieldCount; pos++)  
                {  
                    // some people like ID some id ... assuming case insensitive splits for now  
                    if (splitOn == "*")  
                    {  
                        break;  
                    }  
                    if (string.Equals(reader.GetName(pos), currentSplit, StringComparison.OrdinalIgnoreCase))  
                    {  
                        if (skipFirst)  
                        {  
                            skipFirst = false;  
                        }  
                        else  
                        {  
                            break;  
                        }  
                    }  
                }  
                current = pos;  
                return pos;  
            };  
  
            var deserializers = new List<Func<IDataReader, object>>();  
            int split = 0;  
            bool first = true;  
            foreach (var type in types)  
            {  
                if (type != typeof(DontMap))  
                {  
                    int next = nextSplit(type);  
                    deserializers.Add(GetDeserializer(type, reader, split, next - split, /* returnNullIfFirstMissing: */ !first));  
                    first = false;  
                    split = next;  
                }  
            }  
  
            return deserializers.ToArray();  
        }  
  
        private static CacheInfo GetCacheInfo(Identity identity)  
        {  
            CacheInfo info;  
            if (!TryGetQueryCache(identity, out info))  
            {  
                info = new CacheInfo();  
                if (identity.parametersType != null)  
                {  
                    if (typeof(IDynamicParameters).IsAssignableFrom(identity.parametersType))  
                    {  
                        info.ParamReader = (cmd, obj) => { (obj as IDynamicParameters).AddParameters(cmd, identity); };  
                    }  
#if !CSHARP30  
                    else if (typeof(IEnumerable<KeyValuePair<string, object>>).IsAssignableFrom(identity.parametersType) && typeof(System.Dynamic.IDynamicMetaObjectProvider).IsAssignableFrom(identity.parametersType))  
                    {  
                        info.ParamReader = (cmd, obj) =>  
                        {  
                            IDynamicParameters mapped = new DynamicParameters(obj);  
                            mapped.AddParameters(cmd, identity);  
                        };  
                    }  
#endif  
                    else  
                    {  
                        info.ParamReader = CreateParamInfoGenerator(identity, false, true);  
                    }  
                }  
                SetQueryCache(identity, info);  
            }  
            return info;  
        }  
  
        private static Func<IDataReader, object> GetDeserializer(Type type, IDataReader reader, int startBound, int length, bool returnNullIfFirstMissing)  
        {  
#if !CSHARP30  
            // dynamic is passed in as Object ... by c# design  
            if (type == typeof(object)  
                || type == typeof(DapperRow))  
            {  
                return GetDapperRowDeserializer(reader, startBound, length, returnNullIfFirstMissing);  
            }  
#else  
            if (type.IsAssignableFrom(typeof(Dictionary<string, object>)))  
            {  
                return GetDictionaryDeserializer(reader, startBound, length, returnNullIfFirstMissing);  
            }  
#endif  
            Type underlyingType = null;  
            if (!(typeMap.ContainsKey(type) || type.IsEnum || type.FullName == LinqBinary ||  
                (type.IsValueType && (underlyingType = Nullable.GetUnderlyingType(type)) != null && underlyingType.IsEnum)))  
            {  
                return GetTypeDeserializer(type, reader, startBound, length, returnNullIfFirstMissing);  
            }  
            return GetStructDeserializer(type, underlyingType ?? type, startBound);  
  
        }  
 
#if !CSHARP30  
        private sealed partial class DapperTable  
        {  
            string[] fieldNames;  
            readonly Dictionary<string, int> fieldNameLookup;  
  
            internal string[] FieldNames { get { return fieldNames; } }  
  
            public DapperTable(string[] fieldNames)  
            {  
                if (fieldNames == null) throw new ArgumentNullException("fieldNames");  
                this.fieldNames = fieldNames;  
  
                fieldNameLookup = new Dictionary<string, int>(fieldNames.Length, StringComparer.Ordinal);  
                // if there are dups, we want the **first** key to be the "winner" - so iterate backwards  
                for (int i = fieldNames.Length - 1; i >= 0; i--)  
                {  
                    string key = fieldNames[i];  
                    if (key != null) fieldNameLookup[key] = i;  
                }  
            }  
  
            internal int IndexOfName(string name)  
            {  
                int result;  
                return (name != null && fieldNameLookup.TryGetValue(name, out result)) ? result : -1;  
            }  
            internal int AddField(string name)  
            {  
                if (name == null) throw new ArgumentNullException("name");  
                if (fieldNameLookup.ContainsKey(name)) throw new InvalidOperationException("Field already exists: " + name);  
                int oldLen = fieldNames.Length;  
                Array.Resize(ref fieldNames, oldLen + 1); // yes, this is sub-optimal, but this is not the expected common case  
                fieldNames[oldLen] = name;  
                fieldNameLookup[name] = oldLen;  
                return oldLen;  
            }  
  
  
            internal bool FieldExists(string key)  
            {  
                return key != null && fieldNameLookup.ContainsKey(key);  
            }  
  
            public int FieldCount { get { return fieldNames.Length; } }  
        }  
  
        sealed partial class DapperRowMetaObject : System.Dynamic.DynamicMetaObject  
        {  
            static readonly MethodInfo getValueMethod = typeof(IDictionary<string, object>).GetProperty("Item").GetGetMethod();  
            static readonly MethodInfo setValueMethod = typeof(DapperRow).GetMethod("SetValue", new Type[] { typeof(string), typeof(object) });  
  
            public DapperRowMetaObject(  
                System.Linq.Expressions.Expression expression,  
                System.Dynamic.BindingRestrictions restrictions  
                )  
                : base(expression, restrictions)  
            {  
            }  
  
            public DapperRowMetaObject(  
                System.Linq.Expressions.Expression expression,  
                System.Dynamic.BindingRestrictions restrictions,  
                object value  
                )  
                : base(expression, restrictions, value)  
            {  
            }  
  
            System.Dynamic.DynamicMetaObject CallMethod(  
                MethodInfo method,  
                System.Linq.Expressions.Expression[] parameters  
                )  
            {  
                var callMethod = new System.Dynamic.DynamicMetaObject(  
                    System.Linq.Expressions.Expression.Call(  
                        System.Linq.Expressions.Expression.Convert(Expression, LimitType),  
                        method,  
                        parameters),  
                    System.Dynamic.BindingRestrictions.GetTypeRestriction(Expression, LimitType)  
                    );  
                return callMethod;  
            }  
  
            public override System.Dynamic.DynamicMetaObject BindGetMember(System.Dynamic.GetMemberBinder binder)  
            {  
                var parameters = new System.Linq.Expressions.Expression[]  
                                     {  
                                         System.Linq.Expressions.Expression.Constant(binder.Name)  
                                     };  
  
                var callMethod = CallMethod(getValueMethod, parameters);  
  
                return callMethod;  
            }  
  
            // Needed for Visual basic dynamic support  
            public override System.Dynamic.DynamicMetaObject BindInvokeMember(System.Dynamic.InvokeMemberBinder binder, System.Dynamic.DynamicMetaObject[] args)  
            {  
                var parameters = new System.Linq.Expressions.Expression[]  
                                     {  
                                         System.Linq.Expressions.Expression.Constant(binder.Name)  
                                     };  
  
                var callMethod = CallMethod(getValueMethod, parameters);  
  
                return callMethod;  
            }  
  
            public override System.Dynamic.DynamicMetaObject BindSetMember(System.Dynamic.SetMemberBinder binder, System.Dynamic.DynamicMetaObject value)  
            {  
                var parameters = new System.Linq.Expressions.Expression[]  
                                     {  
                                         System.Linq.Expressions.Expression.Constant(binder.Name),  
                                         value.Expression,  
                                     };  
  
                var callMethod = CallMethod(setValueMethod, parameters);  
  
                return callMethod;  
            }  
        }  
  
        private sealed partial class DapperRow  
            : System.Dynamic.IDynamicMetaObjectProvider  
            , IDictionary<string, object>  
        {  
            readonly DapperTable table;  
            object[] values;  
  
            public DapperRow(DapperTable table, object[] values)  
            {  
                if (table == null) throw new ArgumentNullException("table");  
                if (values == null) throw new ArgumentNullException("values");  
                this.table = table;  
                this.values = values;  
            }  
            private sealed class DeadValue  
            {  
                public static readonly DeadValue Default = new DeadValue();  
                private DeadValue() { }  
            }  
            int ICollection<KeyValuePair<string, object>>.Count  
            {  
                get  
                {  
                    int count = 0;  
                    for (int i = 0; i < values.Length; i++)  
                    {  
                        if (!(values[i] is DeadValue)) count++;  
                    }  
                    return count;  
                }  
            }  
  
            public bool TryGetValue(string name, out object value)  
            {  
                var index = table.IndexOfName(name);  
                if (index < 0)  
                { // doesn't exist  
                    value = null;  
                    return false;  
                }  
                // exists, **even if** we don't have a value; consider table rows heterogeneous  
                value = index < values.Length ? values[index] : null;  
                if (value is DeadValue)  
                { // pretend it isn't here  
                    value = null;  
                    return false;  
                }  
                return true;  
            }  
  
            public override string ToString()  
            {  
                var sb = new StringBuilder("{DapperRow");  
                foreach (var kv in this)  
                {  
                    var value = kv.Value;  
                    sb.Append(", ").Append(kv.Key);  
                    if (value != null)  
                    {  
                        sb.Append(" = '").Append(kv.Value).Append('\'');  
                    }  
                    else  
                    {  
                        sb.Append(" = NULL");  
                    }  
                }  
  
                return sb.Append('}').ToString();  
            }  
  
            System.Dynamic.DynamicMetaObject System.Dynamic.IDynamicMetaObjectProvider.GetMetaObject(  
                System.Linq.Expressions.Expression parameter)  
            {  
                return new DapperRowMetaObject(parameter, System.Dynamic.BindingRestrictions.Empty, this);  
            }  
  
            public IEnumerator<KeyValuePair<string, object>> GetEnumerator()  
            {  
                var names = table.FieldNames;  
                for (var i = 0; i < names.Length; i++)  
                {  
                    object value = i < values.Length ? values[i] : null;  
                    if (!(value is DeadValue))  
                    {  
                        yield return new KeyValuePair<string, object>(names[i], value);  
                    }  
                }  
            }  
  
            IEnumerator IEnumerable.GetEnumerator()  
            {  
                return GetEnumerator();  
            }  
 
        #region Implementation of ICollection<KeyValuePair<string,object>>  
  
            void ICollection<KeyValuePair<string, object>>.Add(KeyValuePair<string, object> item)  
            {  
                IDictionary<string, object> dic = this;  
                dic.Add(item.Key, item.Value);  
            }  
  
            void ICollection<KeyValuePair<string, object>>.Clear()  
            { // removes values for **this row**, but doesn't change the fundamental table  
                for (int i = 0; i < values.Length; i++)  
                    values[i] = DeadValue.Default;  
            }  
  
            bool ICollection<KeyValuePair<string, object>>.Contains(KeyValuePair<string, object> item)  
            {  
                object value;  
                return TryGetValue(item.Key, out value) && Equals(value, item.Value);  
            }  
  
            void ICollection<KeyValuePair<string, object>>.CopyTo(KeyValuePair<string, object>[] array, int arrayIndex)  
            {  
                foreach (var kv in this)  
                {  
                    array[arrayIndex++] = kv; // if they didn't leave enough space; not our fault  
                }  
            }  
  
            bool ICollection<KeyValuePair<string, object>>.Remove(KeyValuePair<string, object> item)  
            {  
                IDictionary<string, object> dic = this;  
                return dic.Remove(item.Key);  
            }  
  
            bool ICollection<KeyValuePair<string, object>>.IsReadOnly  
            {  
                get { return false; }  
            }  
 
            #endregion  
 
        #region Implementation of IDictionary<string,object>  
  
            bool IDictionary<string, object>.ContainsKey(string key)  
            {  
                int index = table.IndexOfName(key);  
                if (index < 0 || index >= values.Length || values[index] is DeadValue) return false;  
                return true;  
            }  
  
            void IDictionary<string, object>.Add(string key, object value)  
            {  
                SetValue(key, value, true);  
            }  
  
            bool IDictionary<string, object>.Remove(string key)  
            {  
                int index = table.IndexOfName(key);  
                if (index < 0 || index >= values.Length || values[index] is DeadValue) return false;  
                values[index] = DeadValue.Default;  
                return true;  
            }  
  
            object IDictionary<string, object>.this[string key]  
            {  
                get { object val; TryGetValue(key, out val); return val; }  
                set { SetValue(key, value, false); }  
            }  
  
            public object SetValue(string key, object value)  
            {  
                return SetValue(key, value, false);  
            }  
            private object SetValue(string key, object value, bool isAdd)  
            {  
                if (key == null) throw new ArgumentNullException("key");  
                int index = table.IndexOfName(key);  
                if (index < 0)  
                {  
                    index = table.AddField(key);  
                }  
                else if (isAdd && index < values.Length && !(values[index] is DeadValue))  
                {  
                    // then semantically, this value already exists  
                    throw new ArgumentException("An item with the same key has already been added", "key");  
                }  
                int oldLength = values.Length;  
                if (oldLength <= index)  
                {  
                    // we'll assume they're doing lots of things, and  
                    // grow it to the full width of the table  
                    Array.Resize(ref values, table.FieldCount);  
                    for (int i = oldLength; i < values.Length; i++)  
                    {  
                        values[i] = DeadValue.Default;  
                    }  
                }  
                return values[index] = value;  
            }  
  
            ICollection<string> IDictionary<string, object>.Keys  
            {  
                get { return this.Select(kv => kv.Key).ToArray(); }  
            }  
  
            ICollection<object> IDictionary<string, object>.Values  
            {  
                get { return this.Select(kv => kv.Value).ToArray(); }  
            }  
 
            #endregion  
        }  
#endif  
        private const string MultiMapSplitExceptionMessage = "When using the multi-mapping APIs ensure you set the splitOn param if you have keys other than Id";  
#if !CSHARP30  
        internal static Func<IDataReader, object> GetDapperRowDeserializer(IDataRecord reader, int startBound, int length, bool returnNullIfFirstMissing)  
        {  
            var fieldCount = reader.FieldCount;  
            if (length == -1)  
            {  
                length = fieldCount - startBound;  
            }  
  
            if (fieldCount <= startBound)  
            {  
                throw new ArgumentException(MultiMapSplitExceptionMessage, "splitOn");  
            }  
  
            var effectiveFieldCount = Math.Min(fieldCount - startBound, length);  
  
            DapperTable table = null;  
  
            return  
                r =>  
                {  
                    if (table == null)  
                    {  
                        string[] names = new string[effectiveFieldCount];  
                        for (int i = 0; i < effectiveFieldCount; i++)  
                        {  
                            names[i] = r.GetName(i + startBound);  
                        }  
                        table = new DapperTable(names);  
                    }  
  
                    var values = new object[effectiveFieldCount];  
  
                    if (returnNullIfFirstMissing)  
                    {  
                        values[0] = r.GetValue(startBound);  
                        if (values[0] is DBNull)  
                        {  
                            return null;  
                        }  
                    }  
  
                    if (startBound == 0)  
                    {  
                        r.GetValues(values);  
                        for (int i = 0; i < values.Length; i++)  
                            if (values[i] is DBNull) values[i] = null;  
                    }  
                    else  
                    {  
                        var begin = returnNullIfFirstMissing ? 1 : 0;  
                        for (var iter = begin; iter < effectiveFieldCount; ++iter)  
                        {  
                            object obj = r.GetValue(iter + startBound);  
                            values[iter] = obj is DBNull ? null : obj;  
                        }  
                    }  
                    return new DapperRow(table, values);  
                };  
        }  
#else  
        internal static Func<IDataReader, object> GetDictionaryDeserializer(IDataRecord reader, int startBound, int length, bool returnNullIfFirstMissing)  
        {  
            var fieldCount = reader.FieldCount;  
            if (length == -1)  
            {  
                length = fieldCount - startBound;  
            }  
  
            if (fieldCount <= startBound)  
            {  
                throw new ArgumentException(MultiMapSplitExceptionMessage, "splitOn");  
            }  
  
            return  
                 r =>  
                 {  
                     IDictionary<string, object> row = new Dictionary<string, object>(length);  
                     for (var i = startBound; i < startBound + length; i++)  
                     {  
                         var tmp = r.GetValue(i);  
                         tmp = tmp == DBNull.Value ? null : tmp;  
                         row[r.GetName(i)] = tmp;  
                         if (returnNullIfFirstMissing && i == startBound && tmp == null)  
                         {  
                             return null;  
                         }  
                     }  
                     return row;  
                 };  
        }  
#endif  
        /// <summary>  
        /// Internal use only  
        /// </summary>  
        /// <param name="value"></param>  
        /// <returns></returns>  
        [Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]  
        [Obsolete("This method is for internal usage only", false)]  
        public static char ReadChar(object value)  
        {  
            if (value == null || value is DBNull) throw new ArgumentNullException("value");  
            string s = value as string;  
            if (s == null || s.Length != 1) throw new ArgumentException("A single-character was expected", "value");  
            return s[0];  
        }  
  
        [Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]  
        [Obsolete("This method is for internal usage only", false)]  
        public static bool ReadBool(object value)  
        {  
            if (value.GetType() != typeof(bool))  
            {  
                return Convert.ToBoolean(value);  
            }  
            else  
                return (bool)value;  
        }  
  
        /// <summary>  
        /// Internal use only  
        /// </summary>  
        [Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]  
        [Obsolete("This method is for internal usage only", false)]  
        public static char? ReadNullableChar(object value)  
        {  
            if (value == null || value is DBNull) return null;  
            string s = value as string;  
            if (s == null || s.Length != 1) throw new ArgumentException("A single-character was expected", "value");  
            return s[0];  
        }  
  
  
        /// <summary>  
        /// Internal use only  
        /// </summary>  
        [Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]  
        [Obsolete("This method is for internal usage only", true)]  
        public static IDbDataParameter FindOrAddParameter(IDataParameterCollection parameters, IDbCommand command, string name)  
        {  
            IDbDataParameter result;  
            if (parameters.Contains(name))  
            {  
                result = (IDbDataParameter)parameters[name];  
            }  
            else  
            {  
                result = command.CreateParameter();  
                result.ParameterName = name;  
                parameters.Add(result);  
            }  
            return result;  
        }  
  
        /// <summary>  
        /// Internal use only  
        /// </summary>  
        [Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]  
        [Obsolete("This method is for internal usage only", false)]  
        public static void PackListParameters(IDbCommand command, string namePrefix, object value)  
        {  
            // initially we tried TVP, however it performs quite poorly.  
            // keep in mind SQL support up to 2000 params easily in sp_executesql, needing more is rare  
  
            var list = value as IEnumerable;  
            var count = 0;  
  
            if (list != null)  
            {  
                if (FeatureSupport.Get(command.Connection).Arrays)  
                {  
                    var arrayParm = command.CreateParameter();  
                    arrayParm.Value = list;  
                    arrayParm.ParameterName = namePrefix;  
                    command.Parameters.Add(arrayParm);  
                }  
                else  
                {  
                    bool isString = value is IEnumerable<string>;  
                    bool isDbString = value is IEnumerable<DbString>;  
                    foreach (var item in list)  
                    {  
                        count++;  
                        var listParam = command.CreateParameter();  
                        listParam.ParameterName = namePrefix + count;  
                        listParam.Value = item ?? DBNull.Value;  
                        if (isString)  
                        {  
                            listParam.Size = 4000;  
                            if (item != null && ((string)item).Length > 4000)  
                            {  
                                listParam.Size = -1;  
                            }  
                        }  
                        if (isDbString && item as DbString != null)  
                        {  
                            var str = item as DbString;  
                            str.AddParameter(command, listParam.ParameterName);  
                        }  
                        else  
                        {  
                            command.Parameters.Add(listParam);  
                        }  
                    }  
  
                    if (count == 0)  
                    {  
                        command.CommandText = Regex.Replace(command.CommandText, @"[?@:]" + Regex.Escape(namePrefix), "(SELECT NULL WHERE 1 = 0)");  
                    }  
                    else  
                    {  
                        command.CommandText = Regex.Replace(command.CommandText, @"[?@:]" + Regex.Escape(namePrefix), match =>  
                        {  
                            var grp = match.Value;  
                            var sb = new StringBuilder("(").Append(grp).Append(1);  
                            for (int i = 2; i <= count; i++)  
                            {  
                                sb.Append(',').Append(grp).Append(i);  
                            }  
                            return sb.Append(')').ToString();  
                        });  
                    }  
                }  
            }  
  
        }  
  
        private static IEnumerable<PropertyInfo> FilterParameters(IEnumerable<PropertyInfo> parameters, string sql)  
        {  
            return parameters.Where(p => Regex.IsMatch(sql, @"[?@:]" + p.Name + "([^a-zA-Z0-9_]+|$)", RegexOptions.IgnoreCase | RegexOptions.Multiline));  
        }  
  
  
        // look for ? / @ / : *by itself*  
        static readonly Regex smellsLikeOleDb = new Regex(@"(?<![a-zA-Z0-9_])[?@:](?![a-zA-Z0-9_])", RegexOptions.Compiled);  
          
        /// <summary>  
        /// Internal use only  
        /// </summary>  
        public static Action<IDbCommand, object> CreateParamInfoGenerator(Identity identity, bool checkForDuplicates, bool removeUnused)  
        {  
            Type type = identity.parametersType;  
              
            bool filterParams = false;  
            if (removeUnused && identity.commandType.GetValueOrDefault(CommandType.Text) == CommandType.Text)  
            {  
                filterParams = !smellsLikeOleDb.IsMatch(identity.sql);  
            }  
            var dm = new DynamicMethod(string.Format("ParamInfo{0}", Guid.NewGuid()), null, new[] { typeof(IDbCommand), typeof(object) }, type, true);  
  
            var il = dm.GetILGenerator();  
  
            il.DeclareLocal(type); // 0  
            bool haveInt32Arg1 = false;  
            il.Emit(OpCodes.Ldarg_1); // stack is now [untyped-param]  
            il.Emit(OpCodes.Unbox_Any, type); // stack is now [typed-param]  
            il.Emit(OpCodes.Stloc_0);// stack is now empty  
  
            il.Emit(OpCodes.Ldarg_0); // stack is now [command]  
            il.EmitCall(OpCodes.Callvirt, typeof(IDbCommand).GetProperty("Parameters").GetGetMethod(), null); // stack is now [parameters]  
  
            var propsArr = type.GetProperties().Where(p => p.GetIndexParameters().Length == 0).ToArray();  
            var ctors = type.GetConstructors();  
            ParameterInfo[] ctorParams;  
            IEnumerable<PropertyInfo> props = null;  
            // try to detect tuple patterns, e.g. anon-types, and use that to choose the order  
            // otherwise: alphabetical  
            if (ctors.Length == 1 && propsArr.Length == (ctorParams = ctors[0].GetParameters()).Length)  
            {  
                // check if reflection was kind enough to put everything in the right order for us  
                bool ok = true;  
                for (int i = 0; i < propsArr.Length; i++)  
                {  
                    if (!string.Equals(propsArr[i].Name, ctorParams[i].Name, StringComparison.InvariantCultureIgnoreCase))  
                    {  
                        ok = false;  
                        break;  
                    }  
                }  
                if(ok)  
                {  
                    // pre-sorted; the reflection gods have smiled upon us  
                    props = propsArr;  
                }  
                else { // might still all be accounted for; check the hard way  
                    var positionByName = new Dictionary<string,int>(StringComparer.InvariantCultureIgnoreCase);  
                    foreach(var param in ctorParams)  
                    {  
                        positionByName[param.Name] = param.Position;  
                    }  
                    if (positionByName.Count == propsArr.Length)  
                    {  
                        int[] positions = new int[propsArr.Length];  
                        ok = true;  
                        for (int i = 0; i < propsArr.Length; i++)  
                        {  
                            int pos;  
                            if (!positionByName.TryGetValue(propsArr[i].Name, out pos))  
                            {  
                                ok = false;  
                                break;  
                            }  
                            positions[i] = pos;  
                        }  
                        if (ok)  
                        {  
                            Array.Sort(positions, propsArr);  
                            props = propsArr;  
                        }  
                    }  
                }  
            }  
            if(props == null) props = propsArr.OrderBy(x => x.Name);  
            if (filterParams)  
            {  
                props = FilterParameters(props, identity.sql);  
            }  
  
            DapperPocoInfo dpi = null;  
            if (identity.type != null)  
            {  
                dpi = identity.type.GetPocoInfo();  
            }  
  
            foreach (var prop in props)  
            {  
                if (filterParams)  
                {  
                    if (identity.sql.IndexOf("@" + prop.Name, StringComparison.InvariantCultureIgnoreCase) < 0  
                        && identity.sql.IndexOf(":" + prop.Name, StringComparison.InvariantCultureIgnoreCase) < 0  
                        && identity.sql.IndexOf("?" + prop.Name, StringComparison.InvariantCultureIgnoreCase) < 0)  
                    { // can't see the parameter in the text (even in a comment, etc) - burn it with fire  
                        continue;  
                    }  
                }  
                if (typeof(ICustomQueryParameter).IsAssignableFrom(prop.PropertyType))  
                {  
                    il.Emit(OpCodes.Ldloc_0); // stack is now [parameters] [typed-param]  
                    il.Emit(OpCodes.Callvirt, prop.GetGetMethod()); // stack is [parameters] [dbstring]  
                    il.Emit(OpCodes.Ldarg_0); // stack is now [parameters] [dbstring] [command]  
                    il.Emit(OpCodes.Ldstr, prop.Name); // stack is now [parameters] [dbstring] [command] [name]  
                    il.EmitCall(OpCodes.Callvirt, prop.PropertyType.GetMethod("AddParameter"), null); // stack is now [parameters]  
                    continue;  
                }  
                DbType dbType = LookupDbType(prop.PropertyType, prop.Name);  
                KeyValuePair<DbType, int>? kvp = null;  
                if (dbType == DbType.String && dpi != null)//默认所有字符串在Dapper中被param成 DbType.String  
                {  
                    kvp = dpi.GetStringColumnMap(prop.Name);  
                }  
                if (dbType == DynamicParameters.EnumerableMultiParameter)  
                {  
                    // this actually represents special handling for list types;  
                    il.Emit(OpCodes.Ldarg_0); // stack is now [parameters] [command]  
                    il.Emit(OpCodes.Ldstr, prop.Name); // stack is now [parameters] [command] [name]  
                    il.Emit(OpCodes.Ldloc_0); // stack is now [parameters] [command] [name] [typed-param]  
                    il.Emit(OpCodes.Callvirt, prop.GetGetMethod()); // stack is [parameters] [command] [name] [typed-value]  
                    if (prop.PropertyType.IsValueType)  
                    {  
                        il.Emit(OpCodes.Box, prop.PropertyType); // stack is [parameters] [command] [name] [boxed-value]  
                    }  
                    il.EmitCall(OpCodes.Call, typeof(SqlMapper).GetMethod("PackListParameters"), null); // stack is [parameters]  
                    continue;  
                }  
                il.Emit(OpCodes.Dup); // stack is now [parameters] [parameters]  
  
                il.Emit(OpCodes.Ldarg_0); // stack is now [parameters] [parameters] [command]  
  
                if (checkForDuplicates)  
                {  
                    // need to be a little careful about adding; use a utility method  
                    il.Emit(OpCodes.Ldstr, prop.Name); // stack is now [parameters] [parameters] [command] [name]  
                    il.EmitCall(OpCodes.Call, typeof(SqlMapper).GetMethod("FindOrAddParameter"), null); // stack is [parameters] [parameter]  
                }  
                else  
                {  
                    // no risk of duplicates; just blindly add  
                    il.EmitCall(OpCodes.Callvirt, typeof(IDbCommand).GetMethod("CreateParameter"), null);// stack is now [parameters] [parameters] [parameter]  
  
                    il.Emit(OpCodes.Dup);// stack is now [parameters] [parameters] [parameter] [parameter]  
                    il.Emit(OpCodes.Ldstr, prop.Name); // stack is now [parameters] [parameters] [parameter] [parameter] [name]  
                    il.EmitCall(OpCodes.Callvirt, typeof(IDataParameter).GetProperty("ParameterName").GetSetMethod(), null);// stack is now [parameters] [parameters] [parameter]  
                }  
                if (dbType != DbType.Time) // https://connect.microsoft.com/VisualStudio/feedback/details/381934/sqlparameter-dbtype-dbtype-time-sets-the-parameter-to-sqldbtype-datetime-instead-of-sqldbtype-time  
                {  
                    //string parameter extensions  对于字符串参数化的扩展  
                    int dbTypeValue = (int)dbType;  
                    if (kvp.HasValue)  
                    {  
                        dbTypeValue = (int)kvp.Value.Key;  
                    }  
  
                    il.Emit(OpCodes.Dup);// stack is now [parameters] [[parameters]] [parameter] [parameter]  
                    EmitInt32(il, dbTypeValue);// stack is now [parameters] [[parameters]] [parameter] [parameter] [db-type]  
  
                    il.EmitCall(OpCodes.Callvirt, typeof(IDataParameter).GetProperty("DbType").GetSetMethod(), null);// stack is now [parameters] [[parameters]] [parameter]  
                }  
  
                il.Emit(OpCodes.Dup);// stack is now [parameters] [[parameters]] [parameter] [parameter]  
                EmitInt32(il, (int)ParameterDirection.Input);// stack is now [parameters] [[parameters]] [parameter] [parameter] [dir]  
                il.EmitCall(OpCodes.Callvirt, typeof(IDataParameter).GetProperty("Direction").GetSetMethod(), null);// stack is now [parameters] [[parameters]] [parameter]  
  
                il.Emit(OpCodes.Dup);// stack is now [parameters] [[parameters]] [parameter] [parameter]  
                il.Emit(OpCodes.Ldloc_0); // stack is now [parameters] [[parameters]] [parameter] [parameter] [typed-param]  
                il.Emit(OpCodes.Callvirt, prop.GetGetMethod()); // stack is [parameters] [[parameters]] [parameter] [parameter] [typed-value]  
                bool checkForNull = true;  
                if (prop.PropertyType.IsValueType)  
                {  
                    il.Emit(OpCodes.Box, prop.PropertyType); // stack is [parameters] [[parameters]] [parameter] [parameter] [boxed-value]  
                    if (Nullable.GetUnderlyingType(prop.PropertyType) == null)  
                    {   // struct but not Nullable<T>; boxed value cannot be null  
                        checkForNull = false;  
                    }  
                }  
                if (checkForNull)  
                {  
                    if (dbType == DbType.String && !haveInt32Arg1)  
                    {  
                        il.DeclareLocal(typeof(int));  
                        haveInt32Arg1 = true;  
                    }  
                    // relative stack: [boxed value]  
                    il.Emit(OpCodes.Dup);// relative stack: [boxed value] [boxed value]  
                    Label notNull = il.DefineLabel();  
                    Label? allDone = dbType == DbType.String ? il.DefineLabel() : (Label?)null;  
                    il.Emit(OpCodes.Brtrue_S, notNull);  
                    // relative stack [boxed value = null]  
                    il.Emit(OpCodes.Pop); // relative stack empty  
                    il.Emit(OpCodes.Ldsfld, typeof(DBNull).GetField("Value")); // relative stack [DBNull]  
                    if (dbType == DbType.String)  
                    {  
                        EmitInt32(il, 0);  
                        il.Emit(OpCodes.Stloc_1);  
                    }  
                    if (allDone != null) il.Emit(OpCodes.Br_S, allDone.Value);  
                    il.MarkLabel(notNull);  
                    //if (prop.PropertyType == typeof(string))  
                    //{  
                    //    il.Emit(OpCodes.Dup); // [string] [string]  
                    //    il.EmitCall(OpCodes.Callvirt, typeof(string).GetProperty("Length").GetGetMethod(), null); // [string] [length]  
                    //    EmitInt32(il, 4000); // [string] [length] [4000]  
                    //    il.Emit(OpCodes.Clt); // [string] [0 or 1]  
                    //    Label isLong = il.DefineLabel(), lenDone = il.DefineLabel();  
                    //    il.Emit(OpCodes.Brtrue_S, isLong);  
                    //    EmitInt32(il, 4000); // [string] [4000]  
                    //    il.Emit(OpCodes.Br_S, lenDone);  
                    //    il.MarkLabel(isLong);  
                    //    EmitInt32(il, -1); // [string] [-1]  
                    //    il.MarkLabel(lenDone);  
                    //    il.Emit(OpCodes.Stloc_1); // [string]   
                    //}  
                    if (prop.PropertyType.FullName == LinqBinary)  
                    {  
                        il.EmitCall(OpCodes.Callvirt, prop.PropertyType.GetMethod("ToArray", BindingFlags.Public | BindingFlags.Instance), null);  
                    }  
                    if (allDone != null) il.MarkLabel(allDone.Value);  
                    // relative stack [boxed value or DBNull]  
                }  
                il.EmitCall(OpCodes.Callvirt, typeof(IDataParameter).GetProperty("Value").GetSetMethod(), null);// stack is now [parameters] [[parameters]] [parameter]  
  
                if (prop.PropertyType == typeof(string))  
                {  
                    //var endOfSize = il.DefineLabel();  
                    //// don't set if 0  
                    //il.Emit(OpCodes.Ldloc_1); // [parameters] [[parameters]] [parameter] [size]  
                    //il.Emit(OpCodes.Brfalse_S, endOfSize); // [parameters] [[parameters]] [parameter]  
  
                    //il.Emit(OpCodes.Dup);// stack is now [parameters] [[parameters]] [parameter] [parameter]  
                    //il.Emit(OpCodes.Ldloc_1); // stack is now [parameters] [[parameters]] [parameter] [parameter] [size]  
                    //il.EmitCall(OpCodes.Callvirt, typeof(IDbDataParameter).GetProperty("Size").GetSetMethod(), null); // stack is now [parameters] [[parameters]] [parameter]  
  
                    //il.MarkLabel(endOfSize);  
  
                    if (kvp.HasValue)  
                    {  
                        il.Emit(OpCodes.Dup);  
                        EmitInt32(il, kvp.Value.Value);  
                        il.EmitCall(OpCodes.Callvirt, typeof(IDbDataParameter).GetProperty("Size").GetSetMethod(), null); // stack is now [parameters] [[parameters]] [parameter]  
                    }  
                }  
                if (checkForDuplicates)  
                {  
                    // stack is now [parameters] [parameter]  
                    il.Emit(OpCodes.Pop); // don't need parameter any more  
                }  
                else  
                {  
                    // stack is now [parameters] [parameters] [parameter]  
                    // blindly add  
                    il.EmitCall(OpCodes.Callvirt, typeof(IList).GetMethod("Add"), null); // stack is now [parameters]  
                    il.Emit(OpCodes.Pop); // IList.Add returns the new index (int); we don't care  
                }  
            }  
            // stack is currently [parameters]  
            il.Emit(OpCodes.Pop); // stack is now empty  
            il.Emit(OpCodes.Ret);  
            return (Action<IDbCommand, object>)dm.CreateDelegate(typeof(Action<IDbCommand, object>));  
        }  
  
        private static IDbCommand SetupCommand(IDbConnection cnn, IDbTransaction transaction, string sql, Action<IDbCommand, object> paramReader, object obj, int? commandTimeout, CommandType? commandType)  
        {  
            var cmd = cnn.CreateCommand();  
            var bindByName = GetBindByName(cmd.GetType());  
            if (bindByName != null) bindByName(cmd, true);  
            if (transaction != null)  
                cmd.Transaction = transaction;  
            cmd.CommandText = sql;  
            if (commandTimeout.HasValue)  
                cmd.CommandTimeout = commandTimeout.Value;  
            if (commandType.HasValue)  
                cmd.CommandType = commandType.Value;  
            if (paramReader != null)  
            {  
                paramReader(cmd, obj);  
            }  
            return cmd;  
        }  
  
  
        private static int ExecuteCommand(IDbConnection cnn, IDbTransaction transaction, string sql, Action<IDbCommand, object> paramReader, object obj, int? commandTimeout, CommandType? commandType)  
        {  
            IDbCommand cmd = null;  
            bool wasClosed = cnn.State == ConnectionState.Closed;  
            try  
            {  
                cmd = SetupCommand(cnn, transaction, sql, paramReader, obj, commandTimeout, commandType);  
                if (wasClosed) cnn.Open();  
                return cmd.ExecuteNonQuery();  
            }  
            finally  
            {  
                if (wasClosed) cnn.Close();  
                if (cmd != null) cmd.Dispose();  
            }  
        }  
  
        private static Func<IDataReader, object> GetStructDeserializer(Type type, Type effectiveType, int index)  
        {  
            // no point using special per-type handling here; it boils down to the same, plus not all are supported anyway (see: SqlDataReader.GetChar - not supported!)  
#pragma warning disable 618  
            if (type == typeof(char))  
            { // this *does* need special handling, though  
                return r => SqlMapper.ReadChar(r.GetValue(index));  
            }  
            if (type == typeof(char?))  
            {  
                return r => SqlMapper.ReadNullableChar(r.GetValue(index));  
            }  
            if (type.FullName == LinqBinary)  
            {  
                return r => Activator.CreateInstance(type, r.GetValue(index));  
            }  
#pragma warning restore 618  
  
            if (effectiveType.IsEnum)  
            {   // assume the value is returned as the correct type (int/byte/etc), but box back to the typed enum  
                return r =>  
                {  
                    var val = r.GetValue(index);  
                    return val is DBNull ? null : Enum.ToObject(effectiveType, val);  
                };  
            }  
            return r =>  
            {  
                var val = r.GetValue(index);  
                return val is DBNull ? null : val;  
            };  
        }  
  
        static readonly MethodInfo  
                    enumParse = typeof(Enum).GetMethod("Parse", new Type[] { typeof(Type), typeof(string), typeof(bool) }),  
                    getItem = typeof(IDataRecord).GetProperties(BindingFlags.Instance | BindingFlags.Public)  
                        .Where(p => p.GetIndexParameters().Any() && p.GetIndexParameters()[0].ParameterType == typeof(int))  
                        .Select(p => p.GetGetMethod()).First();  
  
        /// <summary>  
        /// Gets type-map for the given type  
        /// </summary>  
        /// <returns>Type map implementation, DefaultTypeMap instance if no override present</returns>  
        public static ITypeMap GetTypeMap(Type type)  
        {  
            if (type == null) throw new ArgumentNullException("type");  
            var map = (ITypeMap)_typeMaps[type];  
            if (map == null)  
            {  
                lock (_typeMaps)  
                {   // double-checked; store this to avoid reflection next time we see this type  
                    // since multiple queries commonly use the same domain-entity/DTO/view-model type  
                    map = (ITypeMap)_typeMaps[type];  
                    if (map == null)  
                    {  
                        map = new DefaultTypeMap(type);  
                        _typeMaps[type] = map;  
                    }  
                }  
            }  
            return map;  
        }  
  
        // use Hashtable to get free lockless reading  
        private static readonly Hashtable _typeMaps = new Hashtable();  
  
        /// <summary>  
        /// Set custom mapping for type deserializers  
        /// </summary>  
        /// <param name="type">Entity type to override</param>  
        /// <param name="map">Mapping rules impementation, null to remove custom map</param>  
        public static void SetTypeMap(Type type, ITypeMap map)  
        {  
            if (type == null)  
                throw new ArgumentNullException("type");  
  
            if (map == null || map is DefaultTypeMap)  
            {  
                lock (_typeMaps)  
                {  
                    _typeMaps.Remove(type);  
                }  
            }  
            else  
            {  
                lock (_typeMaps)  
                {  
                    _typeMaps[type] = map;  
                }  
            }  
  
            PurgeQueryCacheByType(type);  
        }  
  
        /// <summary>  
        /// Internal use only  
        /// </summary>  
        /// <param name="type"></param>  
        /// <param name="reader"></param>  
        /// <param name="startBound"></param>  
        /// <param name="length"></param>  
        /// <param name="returnNullIfFirstMissing"></param>  
        /// <returns></returns>  
        public static Func<IDataReader, object> GetTypeDeserializer(  
#if CSHARP30  
Type type, IDataReader reader, int startBound, int length, bool returnNullIfFirstMissing  
#else  
Type type, IDataReader reader, int startBound = 0, int length = -1, bool returnNullIfFirstMissing = false  
#endif  
)  
        {  
  
            var dm = new DynamicMethod(string.Format("Deserialize{0}", Guid.NewGuid()), typeof(object), new[] { typeof(IDataReader) }, true);  
            var il = dm.GetILGenerator();  
            il.DeclareLocal(typeof(int));  
            il.DeclareLocal(type);  
            il.Emit(OpCodes.Ldc_I4_0);  
            il.Emit(OpCodes.Stloc_0);  
  
            if (length == -1)  
            {  
                length = reader.FieldCount - startBound;  
            }  
  
            if (reader.FieldCount <= startBound)  
            {  
                throw new ArgumentException(MultiMapSplitExceptionMessage, "splitOn");  
            }  
  
            var names = Enumerable.Range(startBound, length).Select(i => reader.GetName(i)).ToArray();  
  
            ITypeMap typeMap = GetTypeMap(type);  
  
            int index = startBound;  
  
            ConstructorInfo specializedConstructor = null;  
  
            if (type.IsValueType)  
            {  
                il.Emit(OpCodes.Ldloca_S, (byte)1);  
                il.Emit(OpCodes.Initobj, type);  
            }  
            else  
            {  
                var types = new Type[length];  
                for (int i = startBound; i < startBound + length; i++)  
                {  
                    types[i - startBound] = reader.GetFieldType(i);  
                }  
  
                if (type.IsValueType)  
                {  
                    il.Emit(OpCodes.Ldloca_S, (byte)1);  
                    il.Emit(OpCodes.Initobj, type);  
                }  
                else  
                {  
                    var ctor = typeMap.FindConstructor(names, types);  
                    if (ctor == null)  
                    {  
                        string proposedTypes = "(" + String.Join(", ", types.Select((t, i) => t.FullName + " " + names[i]).ToArray()) + ")";  
                        throw new InvalidOperationException(String.Format("A parameterless default constructor or one matching signature {0} is required for {1} materialization", proposedTypes, type.FullName));  
                    }  
  
                    if (ctor.GetParameters().Length == 0)  
                    {  
                        il.Emit(OpCodes.Newobj, ctor);  
                        il.Emit(OpCodes.Stloc_1);  
                    }  
                    else  
                        specializedConstructor = ctor;  
                }  
            }  
  
            il.BeginExceptionBlock();  
            if (type.IsValueType)  
            {  
                il.Emit(OpCodes.Ldloca_S, (byte)1);// [target]  
            }  
            else if (specializedConstructor == null)  
            {  
                il.Emit(OpCodes.Ldloc_1);// [target]  
            }  
  
            var members = (specializedConstructor != null  
                ? names.Select(n => typeMap.GetConstructorParameter(specializedConstructor, n))  
                : names.Select(n => typeMap.GetMember(n))).ToList();  
  
            // stack is now [target]  
  
            bool first = true;  
            var allDone = il.DefineLabel();  
            int enumDeclareLocal = -1;  
            foreach (var item in members)  
            {  
                if (item != null)  
                {  
                    if (specializedConstructor == null)  
                        il.Emit(OpCodes.Dup); // stack is now [target][target]  
                    Label isDbNullLabel = il.DefineLabel();  
                    Label finishLabel = il.DefineLabel();  
  
                    il.Emit(OpCodes.Ldarg_0); // stack is now [target][target][reader]  
                    EmitInt32(il, index); // stack is now [target][target][reader][index]  
                    il.Emit(OpCodes.Dup);// stack is now [target][target][reader][index][index]  
                    il.Emit(OpCodes.Stloc_0);// stack is now [target][target][reader][index]  
                    il.Emit(OpCodes.Callvirt, getItem); // stack is now [target][target][value-as-object]  
  
                    Type memberType = item.MemberType;  
  
                    if (memberType == typeof(char) || memberType == typeof(char?))  
                    {  
                        il.EmitCall(OpCodes.Call, typeof(SqlMapper).GetMethod(  
                            memberType == typeof(char) ? "ReadChar" : "ReadNullableChar", BindingFlags.Static | BindingFlags.Public), null); // stack is now [target][target][typed-value]  
                    }  
                    else  
                    {  
                        il.Emit(OpCodes.Dup); // stack is now [target][target][value][value]  
                        il.Emit(OpCodes.Isinst, typeof(DBNull)); // stack is now [target][target][value-as-object][DBNull or null]  
                        il.Emit(OpCodes.Brtrue_S, isDbNullLabel); // stack is now [target][target][value-as-object]  
  
                        // unbox nullable enums as the primitive, i.e. byte etc  
  
                        var nullUnderlyingType = Nullable.GetUnderlyingType(memberType);  
                        var unboxType = nullUnderlyingType != null && nullUnderlyingType.IsEnum ? nullUnderlyingType : memberType;  
  
                        if (unboxType.IsEnum)  
                        {  
                            if (enumDeclareLocal == -1)  
                            {  
                                enumDeclareLocal = il.DeclareLocal(typeof(string)).LocalIndex;  
                            }  
  
                            Label isNotString = il.DefineLabel();  
                            il.Emit(OpCodes.Dup); // stack is now [target][target][value][value]  
                            il.Emit(OpCodes.Isinst, typeof(string)); // stack is now [target][target][value-as-object][string or null]  
                            il.Emit(OpCodes.Dup);// stack is now [target][target][value-as-object][string or null][string or null]  
                            StoreLocal(il, enumDeclareLocal); // stack is now [target][target][value-as-object][string or null]  
                            il.Emit(OpCodes.Brfalse_S, isNotString); // stack is now [target][target][value-as-object]  
  
                            il.Emit(OpCodes.Pop); // stack is now [target][target]  
  
                            il.Emit(OpCodes.Ldtoken, unboxType); // stack is now [target][target][enum-type-token]  
                            il.EmitCall(OpCodes.Call, typeof(Type).GetMethod("GetTypeFromHandle"), null);// stack is now [target][target][enum-type]  
                            il.Emit(OpCodes.Ldloc_2); // stack is now [target][target][enum-type][string]  
                            il.Emit(OpCodes.Ldc_I4_1); // stack is now [target][target][enum-type][string][true]  
                            il.EmitCall(OpCodes.Call, enumParse, null); // stack is now [target][target][enum-as-object]  
  
                            il.MarkLabel(isNotString);  
  
                            il.Emit(OpCodes.Unbox_Any, unboxType); // stack is now [target][target][typed-value]  
  
                            if (nullUnderlyingType != null)  
                            {  
                                il.Emit(OpCodes.Newobj, memberType.GetConstructor(new[] { nullUnderlyingType })); // stack is now [target][target][enum-value]  
                            }  
                        }  
                        else if (memberType.FullName == LinqBinary)  
                        {  
                            il.Emit(OpCodes.Unbox_Any, typeof(byte[])); // stack is now [target][target][byte-array]  
                            il.Emit(OpCodes.Newobj, memberType.GetConstructor(new Type[] { typeof(byte[]) }));// stack is now [target][target][binary]  
                        }  
                        else  
                        {  
                            Type dataType = reader.GetFieldType(index);  
                            TypeCode dataTypeCode = Type.GetTypeCode(dataType), unboxTypeCode = Type.GetTypeCode(unboxType);  
                            if (dataType == unboxType || dataTypeCode == unboxTypeCode || dataTypeCode == Type.GetTypeCode(nullUnderlyingType))  
                            {  
                                il.Emit(OpCodes.Unbox_Any, unboxType); // stack is now [target][target][typed-value]  
                            }  
                            else  
                            {  
                                // not a direct match; need to tweak the unbox  
                                MethodInfo op;  
                                if ((op = GetOperator(dataType, nullUnderlyingType ?? unboxType)) != null)  
                                { // this is handy for things like decimal <===> double  
                                    il.Emit(OpCodes.Unbox_Any, dataType); // stack is now [target][target][data-typed-value]  
                                    il.Emit(OpCodes.Call, op); // stack is now [target][target][typed-value]  
                                }  
                                else  
                                {  
                                    bool handled = true;  
                                    OpCode opCode = default(OpCode);  
                                    if (dataTypeCode == TypeCode.Decimal || unboxTypeCode == TypeCode.Decimal)  
                                    {   // no IL level conversions to/from decimal; I guess we could use the static operators, but  
                                        // this feels an edge-case  
                                        handled = false;  
                                    }  
                                    else  
                                    {  
                                        switch (unboxTypeCode)  
                                        {  
                                            case TypeCode.Byte:  
                                                opCode = OpCodes.Conv_Ovf_I1_Un; break;  
                                            case TypeCode.SByte:  
                                                opCode = OpCodes.Conv_Ovf_I1; break;  
                                            case TypeCode.UInt16:  
                                                opCode = OpCodes.Conv_Ovf_I2_Un; break;  
                                            case TypeCode.Int16:  
                                                opCode = OpCodes.Conv_Ovf_I2; break;  
                                            case TypeCode.UInt32:  
                                                opCode = OpCodes.Conv_Ovf_I4_Un; break;  
                                            case TypeCode.Boolean: // boolean is basically an int, at least at this level  
                                            case TypeCode.Int32:  
                                                opCode = OpCodes.Conv_Ovf_I4; break;  
                                            case TypeCode.UInt64:  
                                                opCode = OpCodes.Conv_Ovf_I8_Un; break;  
                                            case TypeCode.Int64:  
                                                opCode = OpCodes.Conv_Ovf_I8; break;  
                                            case TypeCode.Single:  
                                                opCode = OpCodes.Conv_R4; break;  
                                            case TypeCode.Double:  
                                                opCode = OpCodes.Conv_R8; break;  
                                            default:  
                                                handled = false;  
                                                break;  
                                        }  
                                    }  
                                    if (handled)  
                                    { // unbox as the data-type, then use IL-level convert  
                                        il.Emit(OpCodes.Unbox_Any, dataType); // stack is now [target][target][data-typed-value]  
                                        il.Emit(opCode); // stack is now [target][target][typed-value]  
                                        if (unboxTypeCode == TypeCode.Boolean)  
                                        { // compare to zero; I checked "csc" - this is the trick it uses; nice  
                                            il.Emit(OpCodes.Ldc_I4_0);  
                                            il.Emit(OpCodes.Ceq);  
                                            il.Emit(OpCodes.Ldc_I4_0);  
                                            il.Emit(OpCodes.Ceq);  
                                        }  
                                    }  
                                    else  
                                    { // use flexible conversion  
                                        il.Emit(OpCodes.Ldtoken, nullUnderlyingType ?? unboxType); // stack is now [target][target][value][member-type-token]  
                                        il.EmitCall(OpCodes.Call, typeof(Type).GetMethod("GetTypeFromHandle"), null); // stack is now [target][target][value][member-type]  
                                        il.EmitCall(OpCodes.Call, typeof(Convert).GetMethod("ChangeType", new Type[] { typeof(object), typeof(Type) }), null); // stack is now [target][target][boxed-member-type-value]  
                                        il.Emit(OpCodes.Unbox_Any, nullUnderlyingType ?? unboxType); // stack is now [target][target][typed-value]  
                                    }  
                                }  
                                if (nullUnderlyingType != null)  
                                {  
                                    il.Emit(OpCodes.Newobj, unboxType.GetConstructor(new[] { nullUnderlyingType })); // stack is now [target][target][typed-value]  
                                }  
  
                            }  
  
                        }  
                    }  
                    if (specializedConstructor == null)  
                    {  
                        // Store the value in the property/field  
                        if (item.Property != null)  
                        {  
                            if (type.IsValueType)  
                            {  
                                il.Emit(OpCodes.Call, DefaultTypeMap.GetPropertySetter(item.Property, type)); // stack is now [target]  
                            }  
                            else  
                            {  
                                il.Emit(OpCodes.Callvirt, DefaultTypeMap.GetPropertySetter(item.Property, type)); // stack is now [target]  
                            }  
                        }  
                        else  
                        {  
                            il.Emit(OpCodes.Stfld, item.Field); // stack is now [target]  
                        }  
                    }  
  
                    il.Emit(OpCodes.Br_S, finishLabel); // stack is now [target]  
  
                    il.MarkLabel(isDbNullLabel); // incoming stack: [target][target][value]  
                    if (specializedConstructor != null)  
                    {  
                        il.Emit(OpCodes.Pop);  
                        if (item.MemberType.IsValueType)  
                        {  
                            int localIndex = il.DeclareLocal(item.MemberType).LocalIndex;  
                            LoadLocalAddress(il, localIndex);  
                            il.Emit(OpCodes.Initobj, item.MemberType);  
                            LoadLocal(il, localIndex);  
                        }  
                        else  
                        {  
                            il.Emit(OpCodes.Ldnull);  
                        }  
                    }  
                    else  
                    {  
                        il.Emit(OpCodes.Pop); // stack is now [target][target]  
                        il.Emit(OpCodes.Pop); // stack is now [target]  
                    }  
  
                    if (first && returnNullIfFirstMissing)  
                    {  
                        il.Emit(OpCodes.Pop);  
                        il.Emit(OpCodes.Ldnull); // stack is now [null]  
                        il.Emit(OpCodes.Stloc_1);  
                        il.Emit(OpCodes.Br, allDone);  
                    }  
  
                    il.MarkLabel(finishLabel);  
                }  
                first = false;  
                index += 1;  
            }  
            if (type.IsValueType)  
            {  
                il.Emit(OpCodes.Pop);  
            }  
            else  
            {  
                if (specializedConstructor != null)  
                {  
                    il.Emit(OpCodes.Newobj, specializedConstructor);  
                }  
                il.Emit(OpCodes.Stloc_1); // stack is empty  
            }  
            il.MarkLabel(allDone);  
            il.BeginCatchBlock(typeof(Exception)); // stack is Exception  
            il.Emit(OpCodes.Ldloc_0); // stack is Exception, index  
            il.Emit(OpCodes.Ldarg_0); // stack is Exception, index, reader  
            il.EmitCall(OpCodes.Call, typeof(SqlMapper).GetMethod("ThrowDataException"), null);  
            il.EndExceptionBlock();  
  
            il.Emit(OpCodes.Ldloc_1); // stack is [rval]  
            if (type.IsValueType)  
            {  
                il.Emit(OpCodes.Box, type);  
            }  
            il.Emit(OpCodes.Ret);  
  
            return (Func<IDataReader, object>)dm.CreateDelegate(typeof(Func<IDataReader, object>));  
        }  
        static MethodInfo GetOperator(Type from, Type to)  
        {  
            if (to == null) return null;  
            MethodInfo[] fromMethods, toMethods;  
            return ResolveOperator(fromMethods = from.GetMethods(BindingFlags.Static | BindingFlags.Public), from, to, "op_Implicit")  
                ?? ResolveOperator(toMethods = to.GetMethods(BindingFlags.Static | BindingFlags.Public), from, to, "op_Implicit")  
                ?? ResolveOperator(fromMethods, from, to, "op_Explicit")  
                ?? ResolveOperator(toMethods, from, to, "op_Explicit");  
  
        }  
        static MethodInfo ResolveOperator(MethodInfo[] methods, Type from, Type to, string name)  
        {  
            for (int i = 0; i < methods.Length; i++)  
            {  
                if (methods[i].Name != name || methods[i].ReturnType != to) continue;  
                var args = methods[i].GetParameters();  
                if (args.Length != 1 || args[0].ParameterType != from) continue;  
                return methods[i];  
            }  
            return null;  
        }  
  
        private static void LoadLocal(ILGenerator il, int index)  
        {  
            if (index < 0 || index >= short.MaxValue) throw new ArgumentNullException("index");  
            switch (index)  
            {  
                case 0: il.Emit(OpCodes.Ldloc_0); break;  
                case 1: il.Emit(OpCodes.Ldloc_1); break;  
                case 2: il.Emit(OpCodes.Ldloc_2); break;  
                case 3: il.Emit(OpCodes.Ldloc_3); break;  
                default:  
                    if (index <= 255)  
                    {  
                        il.Emit(OpCodes.Ldloc_S, (byte)index);  
                    }  
                    else  
                    {  
                        il.Emit(OpCodes.Ldloc, (short)index);  
                    }  
                    break;  
            }  
        }  
        private static void StoreLocal(ILGenerator il, int index)  
        {  
            if (index < 0 || index >= short.MaxValue) throw new ArgumentNullException("index");  
            switch (index)  
            {  
                case 0: il.Emit(OpCodes.Stloc_0); break;  
                case 1: il.Emit(OpCodes.Stloc_1); break;  
                case 2: il.Emit(OpCodes.Stloc_2); break;  
                case 3: il.Emit(OpCodes.Stloc_3); break;  
                default:  
                    if (index <= 255)  
                    {  
                        il.Emit(OpCodes.Stloc_S, (byte)index);  
                    }  
                    else  
                    {  
                        il.Emit(OpCodes.Stloc, (short)index);  
                    }  
                    break;  
            }  
        }  
        private static void LoadLocalAddress(ILGenerator il, int index)  
        {  
            if (index < 0 || index >= short.MaxValue) throw new ArgumentNullException("index");  
  
            if (index <= 255)  
            {  
                il.Emit(OpCodes.Ldloca_S, (byte)index);  
            }  
            else  
            {  
                il.Emit(OpCodes.Ldloca, (short)index);  
            }  
        }  
        /// <summary>  
        /// Throws a data exception, only used internally  
        /// </summary>  
        /// <param name="ex"></param>  
        /// <param name="index"></param>  
        /// <param name="reader"></param>  
        public static void ThrowDataException(Exception ex, int index, IDataReader reader)  
        {  
            Exception toThrow;  
            try  
            {  
                string name = "(n/a)", value = "(n/a)";  
                if (reader != null && index >= 0 && index < reader.FieldCount)  
                {  
                    name = reader.GetName(index);  
                    object val = reader.GetValue(index);  
                    if (val == null || val is DBNull)  
                    {  
                        value = "<null>";  
                    }  
                    else  
                    {  
                        value = Convert.ToString(val) + " - " + Type.GetTypeCode(val.GetType());  
                    }  
                }  
                toThrow = new DataException(string.Format("Error parsing column {0} ({1}={2})", index, name, value), ex);  
            }  
            catch  
            { // throw the **original** exception, wrapped as DataException  
                toThrow = new DataException(ex.Message, ex);  
            }  
            throw toThrow;  
        }  
        private static void EmitInt32(ILGenerator il, int value)  
        {  
            switch (value)  
            {  
                case -1: il.Emit(OpCodes.Ldc_I4_M1); break;  
                case 0: il.Emit(OpCodes.Ldc_I4_0); break;  
                case 1: il.Emit(OpCodes.Ldc_I4_1); break;  
                case 2: il.Emit(OpCodes.Ldc_I4_2); break;  
                case 3: il.Emit(OpCodes.Ldc_I4_3); break;  
                case 4: il.Emit(OpCodes.Ldc_I4_4); break;  
                case 5: il.Emit(OpCodes.Ldc_I4_5); break;  
                case 6: il.Emit(OpCodes.Ldc_I4_6); break;  
                case 7: il.Emit(OpCodes.Ldc_I4_7); break;  
                case 8: il.Emit(OpCodes.Ldc_I4_8); break;  
                default:  
                    if (value >= -128 && value <= 127)  
                    {  
                        il.Emit(OpCodes.Ldc_I4_S, (sbyte)value);  
                    }  
                    else  
                    {  
                        il.Emit(OpCodes.Ldc_I4, value);  
                    }  
                    break;  
            }  
        }  
  
  
        /// <summary>  
        /// How should connection strings be compared for equivalence? Defaults to StringComparer.Ordinal.  
        /// Providing a custom implementation can be useful for allowing multi-tenancy databases with identical  
        /// schema to share startegies. Note that usual equivalence rules apply: any equivalent connection strings  
        /// <b>MUST</b> yield the same hash-code.  
        /// </summary>  
        public static IEqualityComparer<string> ConnectionStringComparer  
        {  
            get { return connectionStringComparer; }  
            set { connectionStringComparer = value ?? StringComparer.Ordinal; }  
        }  
        private static IEqualityComparer<string> connectionStringComparer = StringComparer.Ordinal;  
  
        /// <summary>  
        /// The grid reader provides interfaces for reading multiple result sets from a Dapper query   
        /// </summary>  
        public partial class GridReader : IDisposable  
        {  
            private IDataReader reader;  
            private IDbCommand command;  
            private Identity identity;  
  
            internal GridReader(IDbCommand command, IDataReader reader, Identity identity)  
            {  
                this.command = command;  
                this.reader = reader;  
                this.identity = identity;  
            }  
 
#if !CSHARP30  
  
            /// <summary>  
            /// Read the next grid of results, returned as a dynamic object  
            /// </summary>  
            public IEnumerable<dynamic> Read(bool buffered = true)  
            {  
                return Read<DapperRow>(buffered);  
            }  
#endif  
 
#if CSHARP30  
            /// <summary>  
            /// Read the next grid of results  
            /// </summary>  
            public IEnumerable<T> Read<T>()  
            {  
                return Read<T>(true);  
            }  
#endif  
            /// <summary>  
            /// Read the next grid of results  
            /// </summary>  
#if CSHARP30  
            public IEnumerable<T> Read<T>(bool buffered)  
#else  
            public IEnumerable<T> Read<T>(bool buffered = true)  
#endif  
            {  
                if (reader == null) throw new ObjectDisposedException(GetType().FullName, "The reader has been disposed; this can happen after all data has been consumed");  
                if (consumed) throw new InvalidOperationException("Query results must be consumed in the correct order, and each result can only be consumed once");  
                var typedIdentity = identity.ForGrid(typeof(T), gridIndex);  
                CacheInfo cache = GetCacheInfo(typedIdentity);  
                var deserializer = cache.Deserializer;  
  
                int hash = GetColumnHash(reader);  
                if (deserializer.Func == null || deserializer.Hash != hash)  
                {  
                    deserializer = new DeserializerState(hash, GetDeserializer(typeof(T), reader, 0, -1, false));  
                    cache.Deserializer = deserializer;  
                }  
                consumed = true;  
                var result = ReadDeferred<T>(gridIndex, deserializer.Func, typedIdentity);  
                return buffered ? result.ToList() : result;  
            }  
  
            private IEnumerable<TReturn> MultiReadInternal<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn>(object func, string splitOn)  
            {  
                var identity = this.identity.ForGrid(typeof(TReturn), new Type[] {   
                    typeof(TFirst),   
                    typeof(TSecond),  
                    typeof(TThird),  
                    typeof(TFourth),  
                    typeof(TFifth),  
                    typeof(TSixth),  
                    typeof(TSeventh)  
                }, gridIndex);  
                try  
                {  
                    foreach (var r in SqlMapper.MultiMapImpl<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn>(null, null, func, null, null, splitOn, null, null, reader, identity))  
                    {  
                        yield return r;  
                    }  
                }  
                finally  
                {  
                    NextResult();  
                }  
            }  
 
#if CSHARP30  
            /// <summary>  
            /// Read multiple objects from a single recordset on the grid  
            /// </summary>  
            public IEnumerable<TReturn> Read<TFirst, TSecond, TReturn>(Func<TFirst, TSecond, TReturn> func, string splitOn)  
            {  
                return Read<TFirst, TSecond, TReturn>(func, splitOn, true);  
            }  
#endif  
            /// <summary>  
            /// Read multiple objects from a single recordset on the grid  
            /// </summary>  
#if CSHARP30  
            public IEnumerable<TReturn> Read<TFirst, TSecond, TReturn>(Func<TFirst, TSecond, TReturn> func, string splitOn, bool buffered)  
#else  
            public IEnumerable<TReturn> Read<TFirst, TSecond, TReturn>(Func<TFirst, TSecond, TReturn> func, string splitOn = "id", bool buffered = true)  
#endif  
            {  
                var result = MultiReadInternal<TFirst, TSecond, DontMap, DontMap, DontMap, DontMap, DontMap, TReturn>(func, splitOn);  
                return buffered ? result.ToList() : result;  
            }  
 
#if CSHARP30  
            /// <summary>  
            /// Read multiple objects from a single recordset on the grid  
            /// </summary>  
            public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TReturn>(Func<TFirst, TSecond, TThird, TReturn> func, string splitOn)  
            {  
                return Read<TFirst, TSecond, TThird, TReturn>(func, splitOn, true);  
            }  
#endif  
            /// <summary>  
            /// Read multiple objects from a single recordset on the grid  
            /// </summary>  
#if CSHARP30  
            public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TReturn>(Func<TFirst, TSecond, TThird, TReturn> func, string splitOn, bool buffered)  
#else  
            public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TReturn>(Func<TFirst, TSecond, TThird, TReturn> func, string splitOn = "id", bool buffered = true)  
#endif  
            {  
                var result = MultiReadInternal<TFirst, TSecond, TThird, DontMap, DontMap, DontMap, DontMap, TReturn>(func, splitOn);  
                return buffered ? result.ToList() : result;  
            }  
 
#if CSHARP30  
            /// <summary>  
            /// Read multiple objects from a single record set on the grid  
            /// </summary>  
            public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TFourth, TReturn>(Func<TFirst, TSecond, TThird, TFourth, TReturn> func, string splitOn)  
            {  
                return Read<TFirst, TSecond, TThird, TFourth, TReturn>(func, splitOn, true);  
            }  
#endif  
  
            /// <summary>  
            /// Read multiple objects from a single record set on the grid  
            /// </summary>  
#if CSHARP30  
            public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TFourth, TReturn>(Func<TFirst, TSecond, TThird, TFourth, TReturn> func, string splitOn, bool buffered)  
#else  
            public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TFourth, TReturn>(Func<TFirst, TSecond, TThird, TFourth, TReturn> func, string splitOn = "id", bool buffered = true)  
#endif  
            {  
                var result = MultiReadInternal<TFirst, TSecond, TThird, TFourth, DontMap, DontMap, DontMap, TReturn>(func, splitOn);  
                return buffered ? result.ToList() : result;  
            }  
 
 
 
#if !CSHARP30  
            /// <summary>  
            /// Read multiple objects from a single record set on the grid  
            /// </summary>  
            public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(Func<TFirst, TSecond, TThird, TFourth, TFifth, TReturn> func, string splitOn = "id", bool buffered = true)  
            {  
                var result = MultiReadInternal<TFirst, TSecond, TThird, TFourth, TFifth, DontMap, DontMap, TReturn>(func, splitOn);  
                return buffered ? result.ToList() : result;  
            }  
            /// <summary>  
            /// Read multiple objects from a single record set on the grid  
            /// </summary>  
            public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TReturn>(Func<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TReturn> func, string splitOn = "id", bool buffered = true)  
            {  
                var result = MultiReadInternal<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, DontMap, TReturn>(func, splitOn);  
                return buffered ? result.ToList() : result;  
            }  
            /// <summary>  
            /// Read multiple objects from a single record set on the grid  
            /// </summary>  
            public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn>(Func<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn> func, string splitOn = "id", bool buffered = true)  
            {  
                var result = MultiReadInternal<TFirst, TSecond, TThird, TFourth, TFifth, TSixth, TSeventh, TReturn>(func, splitOn);  
                return buffered ? result.ToList() : result;  
            }  
#endif  
  
            private IEnumerable<T> ReadDeferred<T>(int index, Func<IDataReader, object> deserializer, Identity typedIdentity)  
            {  
                try  
                {  
                    while (index == gridIndex && reader.Read())  
                    {  
                        yield return (T)deserializer(reader);  
                    }  
                }  
                finally // finally so that First etc progresses things even when multiple rows  
                {  
                    if (index == gridIndex)  
                    {  
                        NextResult();  
                    }  
                }  
            }  
            private int gridIndex, readCount;  
            private bool consumed;  
            private void NextResult()  
            {  
                if (reader.NextResult())  
                {  
                    readCount++;  
                    gridIndex++;  
                    consumed = false;  
                }  
                else  
                {  
                    // happy path; close the reader cleanly - no  
                    // need for "Cancel" etc  
                    reader.Dispose();  
                    reader = null;  
  
                    Dispose();  
                }  
  
            }  
            /// <summary>  
            /// Dispose the grid, closing and disposing both the underlying reader and command.  
            /// </summary>  
            public void Dispose()  
            {  
                if (reader != null)  
                {  
                    if (!reader.IsClosed && command != null) command.Cancel();  
                    reader.Dispose();  
                    reader = null;  
                }  
                if (command != null)  
                {  
                    command.Dispose();  
                    command = null;  
                }  
            }  
        }  
    }  
  
    /// <summary>  
    /// A bag of parameters that can be passed to the Dapper Query and Execute methods  
    /// </summary>  
    partial class DynamicParameters : SqlMapper.IDynamicParameters  
    {  
        internal const DbType EnumerableMultiParameter = (DbType)(-1);  
        static Dictionary<SqlMapper.Identity, Action<IDbCommand, object>> paramReaderCache = new Dictionary<SqlMapper.Identity, Action<IDbCommand, object>>();  
  
        Dictionary<string, ParamInfo> parameters = new Dictionary<string, ParamInfo>();  
        List<object> templates;  
  
        partial class ParamInfo  
        {  
            public string Name { get; set; }  
            public object Value { get; set; }  
            public ParameterDirection ParameterDirection { get; set; }  
            public DbType? DbType { get; set; }  
            public int? Size { get; set; }  
            public IDbDataParameter AttachedParam { get; set; }  
        }  
  
        /// <summary>  
        /// construct a dynamic parameter bag  
        /// </summary>  
        public DynamicParameters()  
        {  
            RemoveUnused = true;  
        }  
  
        /// <summary>  
        /// construct a dynamic parameter bag  
        /// </summary>  
        /// <param name="template">can be an anonymous type or a DynamicParameters bag</param>  
        public DynamicParameters(object template)  
        {  
            RemoveUnused = true;  
            AddDynamicParams(template);  
        }  
  
        /// <summary>  
        /// Append a whole object full of params to the dynamic  
        /// EG: AddDynamicParams(new {A = 1, B = 2}) // will add property A and B to the dynamic  
        /// </summary>  
        /// <param name="param"></param>  
        public void AddDynamicParams(  
#if CSHARP30  
object param  
#else  
dynamic param  
#endif  
)  
        {  
            var obj = param as object;  
            if (obj != null)  
            {  
                var subDynamic = obj as DynamicParameters;  
                if (subDynamic == null)  
                {  
                    var dictionary = obj as IEnumerable<KeyValuePair<string, object>>;  
                    if (dictionary == null)  
                    {  
                        templates = templates ?? new List<object>();  
                        templates.Add(obj);  
                    }  
                    else  
                    {  
                        foreach (var kvp in dictionary)  
                        {  
#if CSHARP30  
                            Add(kvp.Key, kvp.Value, null, null, null);  
#else  
                            Add(kvp.Key, kvp.Value);  
#endif  
                        }  
                    }  
                }  
                else  
                {  
                    if (subDynamic.parameters != null)  
                    {  
                        foreach (var kvp in subDynamic.parameters)  
                        {  
                            parameters.Add(kvp.Key, kvp.Value);  
                        }  
                    }  
  
                    if (subDynamic.templates != null)  
                    {  
                        templates = templates ?? new List<object>();  
                        foreach (var t in subDynamic.templates)  
                        {  
                            templates.Add(t);  
                        }  
                    }  
                }  
            }  
        }  
  
        /// <summary>  
        /// Add a parameter to this dynamic parameter list  
        /// </summary>  
        /// <param name="name"></param>  
        /// <param name="value"></param>  
        /// <param name="dbType"></param>  
        /// <param name="direction"></param>  
        /// <param name="size"></param>  
        public void Add(  
#if CSHARP30  
string name, object value, DbType? dbType, ParameterDirection? direction, int? size  
#else  
string name, object value = null, DbType? dbType = null, ParameterDirection? direction = null, int? size = null  
#endif  
)  
        {  
            parameters[Clean(name)] = new ParamInfo() { Name = name, Value = value, ParameterDirection = direction ?? ParameterDirection.Input, DbType = dbType, Size = size };  
        }  
  
        static string Clean(string name)  
        {  
            if (!string.IsNullOrEmpty(name))  
            {  
                switch (name[0])  
                {  
                    case '@':  
                    case ':':  
                    case '?':  
                        return name.Substring(1);  
                }  
            }  
            return name;  
        }  
  
        void SqlMapper.IDynamicParameters.AddParameters(IDbCommand command, SqlMapper.Identity identity)  
        {  
            AddParameters(command, identity);  
        }  
  
        /// <summary>  
        /// If true, the command-text is inspected and only values that are clearly used are included on the connection  
        /// </summary>  
        public bool RemoveUnused { get; set; }  
  
        /// <summary>  
        /// Add all the parameters needed to the command just before it executes  
        /// </summary>  
        /// <param name="command">The raw command prior to execution</param>  
        /// <param name="identity">Information about the query</param>  
        protected void AddParameters(IDbCommand command, SqlMapper.Identity identity)  
        {  
            if (templates != null)  
            {  
                foreach (var template in templates)  
                {  
                    var newIdent = identity.ForDynamicParameters(template.GetType());  
                    Action<IDbCommand, object> appender;  
  
                    lock (paramReaderCache)  
                    {  
                        if (!paramReaderCache.TryGetValue(newIdent, out appender))  
                        {  
                            appender = SqlMapper.CreateParamInfoGenerator(newIdent, true, RemoveUnused);  
                            paramReaderCache[newIdent] = appender;  
                        }  
                    }  
  
                    appender(command, template);  
                }  
            }  
  
            foreach (var param in parameters.Values)  
            {  
                var dbType = param.DbType;  
                var val = param.Value;  
                string name = Clean(param.Name);  
  
                if (dbType == null && val != null) dbType = SqlMapper.LookupDbType(val.GetType(), name);  
  
                if (dbType == DynamicParameters.EnumerableMultiParameter)  
                {  
#pragma warning disable 612, 618  
                    SqlMapper.PackListParameters(command, name, val);  
#pragma warning restore 612, 618  
                }  
                else  
                {  
  
                    bool add = !command.Parameters.Contains(name);  
                    IDbDataParameter p;  
                    if (add)  
                    {  
                        p = command.CreateParameter();  
                        p.ParameterName = name;  
                    }  
                    else  
                    {  
                        p = (IDbDataParameter)command.Parameters[name];  
                    }  
  
                    p.Value = val ?? DBNull.Value;  
                    p.Direction = param.ParameterDirection;  
                    var s = val as string;  
                    if (s != null)  
                    {  
                        if (s.Length <= 4000)  
                        {  
                            p.Size = 4000;  
                        }  
                    }  
                    if (param.Size != null)  
                    {  
                        p.Size = param.Size.Value;  
                    }  
                    if (dbType != null)  
                    {  
                        p.DbType = dbType.Value;  
                    }  
                    if (add)  
                    {  
                        command.Parameters.Add(p);  
                    }  
                    param.AttachedParam = p;  
                }  
  
            }  
        }  
  
        /// <summary>  
        /// All the names of the param in the bag, use Get to yank them out  
        /// </summary>  
        public IEnumerable<string> ParameterNames  
        {  
            get  
            {  
                return parameters.Select(p => p.Key);  
            }  
        }  
  
  
        /// <summary>  
        /// Get the value of a parameter  
        /// </summary>  
        /// <typeparam name="T"></typeparam>  
        /// <param name="name"></param>  
        /// <returns>The value, note DBNull.Value is not returned, instead the value is returned as null</returns>  
        public T Get<T>(string name)  
        {  
            var val = parameters[Clean(name)].AttachedParam.Value;  
            if (val == DBNull.Value)  
            {  
                if (default(T) != null)  
                {  
                    throw new ApplicationException("Attempting to cast a DBNull to a non nullable type!");  
                }  
                return default(T);  
            }  
            return (T)val;  
        }  
    }  
  
    /// <summary>  
    /// This class represents a SQL string, it can be used if you need to denote your parameter is a Char vs VarChar vs nVarChar vs nChar  
    /// </summary>  
    sealed partial class DbString : Dapper.SqlMapper.ICustomQueryParameter  
    {  
        /// <summary>  
        /// Create a new DbString  
        /// </summary>  
        public DbString() { Length = -1; }  
        /// <summary>  
        /// Ansi vs Unicode   
        /// </summary>  
        public bool IsAnsi { get; set; }  
        /// <summary>  
        /// Fixed length   
        /// </summary>  
        public bool IsFixedLength { get; set; }  
        /// <summary>  
        /// Length of the string -1 for max  
        /// </summary>  
        public int Length { get; set; }  
        /// <summary>  
        /// The value of the string  
        /// </summary>  
        public string Value { get; set; }  
        /// <summary>  
        /// Add the parameter to the command... internal use only  
        /// </summary>  
        /// <param name="command"></param>  
        /// <param name="name"></param>  
        public void AddParameter(IDbCommand command, string name)  
        {  
            if (IsFixedLength && Length == -1)  
            {  
                throw new InvalidOperationException("If specifying IsFixedLength,  a Length must also be specified");  
            }  
            var param = command.CreateParameter();  
            param.ParameterName = name;  
            param.Value = (object)Value ?? DBNull.Value;  
            if (Length == -1 && Value != null && Value.Length <= 4000)  
            {  
                param.Size = 4000;  
            }  
            else  
            {  
                param.Size = Length;  
            }  
            param.DbType = IsAnsi ? (IsFixedLength ? DbType.AnsiStringFixedLength : DbType.AnsiString) : (IsFixedLength ? DbType.StringFixedLength : DbType.String);  
            command.Parameters.Add(param);  
        }  
    }  
  
    /// <summary>  
    /// Handles variances in features per DBMS  
    /// </summary>  
    partial class FeatureSupport  
    {  
        /// <summary>  
        /// Dictionary of supported features index by connection type name  
        /// </summary>  
        private static readonly Dictionary<string, FeatureSupport> FeatureList = new Dictionary<string, FeatureSupport>(StringComparer.InvariantCultureIgnoreCase) {  
                {"sqlserverconnection", new FeatureSupport { Arrays = false}},  
                {"npgsqlconnection", new FeatureSupport {Arrays = true}}  
        };  
  
        /// <summary>  
        /// Gets the featureset based on the passed connection  
        /// </summary>  
        public static FeatureSupport Get(IDbConnection connection)  
        {  
            string name = connection.GetType().Name;  
            FeatureSupport features;  
            return FeatureList.TryGetValue(name, out features) ? features : FeatureList.Values.First();  
        }  
  
        /// <summary>  
        /// True if the db supports array columns e.g. Postgresql  
        /// </summary>  
        public bool Arrays { get; set; }  
    }  
  
    /// <summary>  
    /// Represents simple memeber map for one of target parameter or property or field to source DataReader column  
    /// </summary>  
    sealed partial class SimpleMemberMap : SqlMapper.IMemberMap  
    {  
        private readonly string _columnName;  
        private readonly PropertyInfo _property;  
        private readonly FieldInfo _field;  
        private readonly ParameterInfo _parameter;  
  
        /// <summary>  
        /// Creates instance for simple property mapping  
        /// </summary>  
        /// <param name="columnName">DataReader column name</param>  
        /// <param name="property">Target property</param>  
        public SimpleMemberMap(string columnName, PropertyInfo property)  
        {  
            if (columnName == null)  
                throw new ArgumentNullException("columnName");  
  
            if (property == null)  
                throw new ArgumentNullException("property");  
  
            _columnName = columnName;  
            _property = property;  
        }  
  
        /// <summary>  
        /// Creates instance for simple field mapping  
        /// </summary>  
        /// <param name="columnName">DataReader column name</param>  
        /// <param name="field">Target property</param>  
        public SimpleMemberMap(string columnName, FieldInfo field)  
        {  
            if (columnName == null)  
                throw new ArgumentNullException("columnName");  
  
            if (field == null)  
                throw new ArgumentNullException("field");  
  
            _columnName = columnName;  
            _field = field;  
        }  
  
        /// <summary>  
        /// Creates instance for simple constructor parameter mapping  
        /// </summary>  
        /// <param name="columnName">DataReader column name</param>  
        /// <param name="parameter">Target constructor parameter</param>  
        public SimpleMemberMap(string columnName, ParameterInfo parameter)  
        {  
            if (columnName == null)  
                throw new ArgumentNullException("columnName");  
  
            if (parameter == null)  
                throw new ArgumentNullException("parameter");  
  
            _columnName = columnName;  
            _parameter = parameter;  
        }  
  
        /// <summary>  
        /// DataReader column name  
        /// </summary>  
        public string ColumnName  
        {  
            get { return _columnName; }  
        }  
  
        /// <summary>  
        /// Target member type  
        /// </summary>  
        public Type MemberType  
        {  
            get  
            {  
                if (_field != null)  
                    return _field.FieldType;  
  
                if (_property != null)  
                    return _property.PropertyType;  
  
                if (_parameter != null)  
                    return _parameter.ParameterType;  
  
                return null;  
            }  
        }  
  
        /// <summary>  
        /// Target property  
        /// </summary>  
        public PropertyInfo Property  
        {  
            get { return _property; }  
        }  
  
        /// <summary>  
        /// Target field  
        /// </summary>  
        public FieldInfo Field  
        {  
            get { return _field; }  
        }  
  
        /// <summary>  
        /// Target constructor parameter  
        /// </summary>  
        public ParameterInfo Parameter  
        {  
            get { return _parameter; }  
        }  
    }  
  
    /// <summary>  
    /// Represents default type mapping strategy used by Dapper  
    /// </summary>  
    sealed partial class DefaultTypeMap : SqlMapper.ITypeMap  
    {  
        private readonly List<FieldInfo> _fields;  
        private readonly List<PropertyInfo> _properties;  
        private readonly Type _type;  
  
        /// <summary>  
        /// Creates default type map  
        /// </summary>  
        /// <param name="type">Entity type</param>  
        public DefaultTypeMap(Type type)  
        {  
            if (type == null)  
                throw new ArgumentNullException("type");  
  
            _fields = GetSettableFields(type);  
            _properties = GetSettableProps(type);  
            _type = type;  
        }  
  
        internal static MethodInfo GetPropertySetter(PropertyInfo propertyInfo, Type type)  
        {  
            return propertyInfo.DeclaringType == type ?  
                propertyInfo.GetSetMethod(true) :  
                propertyInfo.DeclaringType.GetProperty(propertyInfo.Name, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance).GetSetMethod(true);  
        }  
  
        internal static List<PropertyInfo> GetSettableProps(Type t)  
        {  
            return t  
                  .GetProperties(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)  
                  .Where(p => GetPropertySetter(p, t) != null)  
                  .ToList();  
        }  
  
        internal static List<FieldInfo> GetSettableFields(Type t)  
        {  
            return t.GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance).ToList();  
        }  
  
        /// <summary>  
        /// Finds best constructor  
        /// </summary>  
        /// <param name="names">DataReader column names</param>  
        /// <param name="types">DataReader column types</param>  
        /// <returns>Matching constructor or default one</returns>  
        public ConstructorInfo FindConstructor(string[] names, Type[] types)  
        {  
            var constructors = _type.GetConstructors(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);  
            foreach (ConstructorInfo ctor in constructors.OrderBy(c => c.IsPublic ? 0 : (c.IsPrivate ? 2 : 1)).ThenBy(c => c.GetParameters().Length))  
            {  
                ParameterInfo[] ctorParameters = ctor.GetParameters();  
                if (ctorParameters.Length == 0)  
                    return ctor;  
  
                if (ctorParameters.Length != types.Length)  
                    continue;  
  
                int i = 0;  
                for (; i < ctorParameters.Length; i++)  
                {  
                    if (!String.Equals(ctorParameters[i].Name, names[i], StringComparison.OrdinalIgnoreCase))  
                        break;  
                    if (types[i] == typeof(byte[]) && ctorParameters[i].ParameterType.FullName == SqlMapper.LinqBinary)  
                        continue;  
                    var unboxedType = Nullable.GetUnderlyingType(ctorParameters[i].ParameterType) ?? ctorParameters[i].ParameterType;  
                    if (unboxedType != types[i]  
                        && !(unboxedType.IsEnum && Enum.GetUnderlyingType(unboxedType) == types[i])  
                        && !(unboxedType == typeof(char) && types[i] == typeof(string)))  
                        break;  
                }  
  
                if (i == ctorParameters.Length)  
                    return ctor;  
            }  
  
            return null;  
        }  
  
        /// <summary>  
        /// Gets mapping for constructor parameter  
        /// </summary>  
        /// <param name="constructor">Constructor to resolve</param>  
        /// <param name="columnName">DataReader column name</param>  
        /// <returns>Mapping implementation</returns>  
        public SqlMapper.IMemberMap GetConstructorParameter(ConstructorInfo constructor, string columnName)  
        {  
            var parameters = constructor.GetParameters();  
  
            return new SimpleMemberMap(columnName, parameters.FirstOrDefault(p => string.Equals(p.Name, columnName, StringComparison.OrdinalIgnoreCase)));  
        }  
  
        /// <summary>  
        /// Gets member mapping for column  
        /// </summary>  
        /// <param name="columnName">DataReader column name</param>  
        /// <returns>Mapping implementation</returns>  
        public SqlMapper.IMemberMap GetMember(string columnName)  
        {  
            var property = _properties.FirstOrDefault(p => string.Equals(p.Name, columnName, StringComparison.Ordinal))  
               ?? _properties.FirstOrDefault(p => string.Equals(p.Name, columnName, StringComparison.OrdinalIgnoreCase));  
  
            if (property != null)  
                return new SimpleMemberMap(columnName, property);  
  
            var field = _fields.FirstOrDefault(p => string.Equals(p.Name, columnName, StringComparison.Ordinal))  
               ?? _fields.FirstOrDefault(p => string.Equals(p.Name, columnName, StringComparison.OrdinalIgnoreCase));  
  
            if (field != null)  
                return new SimpleMemberMap(columnName, field);  
  
            return null;  
        }  
    }  
  
    /// <summary>  
    /// Implements custom property mapping by user provided criteria (usually presence of some custom attribute with column to member mapping)  
    /// </summary>  
    sealed partial class CustomPropertyTypeMap : SqlMapper.ITypeMap  
    {  
        private readonly Type _type;  
        private readonly Func<Type, string, PropertyInfo> _propertySelector;  
  
        /// <summary>  
        /// Creates custom property mapping  
        /// </summary>  
        /// <param name="type">Target entity type</param>  
        /// <param name="propertySelector">Property selector based on target type and DataReader column name</param>  
        public CustomPropertyTypeMap(Type type, Func<Type, string, PropertyInfo> propertySelector)  
        {  
            if (type == null)  
                throw new ArgumentNullException("type");  
  
            if (propertySelector == null)  
                throw new ArgumentNullException("propertySelector");  
  
            _type = type;  
            _propertySelector = propertySelector;  
        }  
  
        /// <summary>  
        /// Always returns default constructor  
        /// </summary>  
        /// <param name="names">DataReader column names</param>  
        /// <param name="types">DataReader column types</param>  
        /// <returns>Default constructor</returns>  
        public ConstructorInfo FindConstructor(string[] names, Type[] types)  
        {  
            return _type.GetConstructor(new Type[0]);  
        }  
  
        /// <summary>  
        /// Not impelmeneted as far as default constructor used for all cases  
        /// </summary>  
        /// <param name="constructor"></param>  
        /// <param name="columnName"></param>  
        /// <returns></returns>  
        public SqlMapper.IMemberMap GetConstructorParameter(ConstructorInfo constructor, string columnName)  
        {  
            throw new NotSupportedException();  
        }  
  
        /// <summary>  
        /// Returns property based on selector strategy  
        /// </summary>  
        /// <param name="columnName">DataReader column name</param>  
        /// <returns>Poperty member map</returns>  
        public SqlMapper.IMemberMap GetMember(string columnName)  
        {  
            var prop = _propertySelector(_type, columnName);  
            return prop != null ? new SimpleMemberMap(columnName, prop) : null;  
        }  
    }  
  
    // Define DAPPER_MAKE_PRIVATE if you reference Dapper by source  
    // and you like to make the Dapper types private (in order to avoid  
    // conflicts with other projects that also reference Dapper by source)  
#if !DAPPER_MAKE_PRIVATE  
  
    public partial class SqlMapper  
    {  
    }  
  
    public partial class DynamicParameters  
    {  
  
    }  
  
    public partial class DbString  
    {  
  
    }  
  
    public partial class SimpleMemberMap  
    {  
  
    }  
  
    public partial class DefaultTypeMap  
    {  
  
    }  
  
    public partial class CustomPropertyTypeMap  
    {  
  
    }  
  
    public partial class FeatureSupport  
    {  
  
    }  
 
#endif  
  
}  

Nunits测试代码

1、对数据操作部分的测试

using System;  
using System.Linq;  
using NUnit.Framework;  
using System.Data.SqlClient;  
using Dapper;  
using System.Collections;  
using System.Collections.Generic;  
  
namespace DapperTest.DapperExtensions  
{  
    [Serializable]  
    public class AutoCreate  
    {  
        public int ID { get; set; }  
        public string Name { get; set; }  
    }  
    [TestFixture]  
    public class DataOperateTest  
    {  
        private static string connectionStr = @"Server=W-PC\DEMO; Database=ByteartRetail; Integrated Security=True; MultipleActiveResultSets=True;";  
        SqlConnection conn;  
        [TestFixtureSetUp]  
        public void InitSqlConnection()  
        {  
            DapperPocoInfo dpi = typeof(AutoCreate).GetPocoInfo();  
            dpi.AddStringColumnMap("Name");  
            dpi.TableName = "Tbl_AutoCreate";  
  
            conn = new SqlConnection(connectionStr);  
            conn.Open();  
        }  
  
        [TestFixtureTearDown]  
        public void CloseConnection()  
        {  
            conn.Close();  
        }  
        [Test]  
        public void IUQDTypedTest()  
        {  
            AutoCreate poco = new AutoCreate();  
            poco.Name = DateTime.Now.ToString("yyMMddHHmmssfff");  
            bool success = conn.Insert<AutoCreate>(poco);  
            Assert.AreEqual(success, true);  
            Assert.AreNotEqual(0, poco.ID);  
  
            poco.Name = "UU" + DateTime.Now.ToString("yyMMddHHmmssfff");  
            success = conn.Update<AutoCreate>(poco);  
            Assert.AreEqual(success, true);  
  
            AutoCreate pocoQuery = conn.QueryByKey<AutoCreate>(new { ID = poco.ID });  
            Assert.AreEqual(poco.Name, pocoQuery.Name);  
  
            success = conn.DeleteByKey<AutoCreate>(new { ID = poco.ID });  
            Assert.AreEqual(true, success);  
  
            pocoQuery = conn.QueryByKey<AutoCreate>(poco);  
            Assert.IsNull(pocoQuery);  
        }  
  
        [Test]  
        public void IUQDDynamicTest()  
        {  
            //AutoCreate tmp = new AutoCreate();  
            string name = DateTime.Now.ToString("yyMMddHHmmssfff");  
            var poco = new { ID = 0, Name = name };  
            MsSqlServerAdapter adapter = (MsSqlServerAdapter)conn.GetSqlAdapter();  
            bool success = adapter.Insert<AutoCreate>(conn, poco);  
            Assert.AreEqual(success, true);  
            //Assert.AreNotEqual(0, poco.ID);  
            int id;  
            //id = adapter.GetLastInsertID<AutoCreate>(conn);  
            id = (int)conn.GetLastInsertIndentityID<AutoCreate>();  
            Assert.Greater(id, 0);  
  
            AutoCreate pocoQuery = conn.QueryByKey<AutoCreate>(new { ID = id });  
            Assert.AreEqual(poco.Name, pocoQuery.Name);//测试插入的数据是否正确  
  
            name = "UU" + DateTime.Now.ToString("yyMMddHHmmssfff");  
            //success = adapter.UpdateByKey<AutoCreate>(conn, new { ID = id, Name = name });  
            success = conn.Update<AutoCreate>(new { ID = id, Name = name });  
            Assert.AreEqual(success, true);  
  
            pocoQuery = conn.QueryByKey<AutoCreate>(new { ID = id });  
            Assert.AreEqual(name, pocoQuery.Name);//测试插入的数据是否正确  
  
            success = conn.DeleteByKey<AutoCreate>(new { ID = id });  
            Assert.AreEqual(true, success);  
  
            pocoQuery = conn.QueryByKey<AutoCreate>(new { ID = id });  
            Assert.IsNull(pocoQuery);  
        }  
    }  
}  
 

2、对POCO扩展部分的测试

using System;  
  
namespace DapperTest  
{  
    [Serializable]  
    public class TestEndWithIDModel  
    {  
        public byte ID { get; set; }  
        public string Name { get; set; }  
    }  
    [Serializable]  
    public class TestNotEndWithIDModel  
    {  
        public int OrderNum { get; set; }  
        public string OrderName { get; set; }  
    }  
}  

对ID结尾的主键测试

using System.Linq;  
using NUnit.Framework;  
using Dapper;  
  
namespace DapperTest.PocoInfo  
{  
    [TestFixture]  
    public class PocoInfoEndWithIDKeyTest  
    {  
        DapperPocoInfo dpi;  
        [SetUp]  
        public void GetDapperPocoInfo()  
        {  
            dpi = typeof(TestEndWithIDModel).GetPocoInfo();  
            //dpi.AddKeyMap("ID");//此行代码注销以下测试也是正确的  
        }  
        [Test]  
        public void TestModelKeyOnlyOneTest()  
        {  
            Assert.AreEqual(1, dpi.KeyProperties.Count());  
            Assert.AreEqual("ID", dpi.KeyProperties.First().Name);  
            Assert.AreEqual(true, dpi.IsUnWriteKey());  
        }  
    }  
}  

非ID结尾的主键测试

using System.Linq;  
using NUnit.Framework;  
using Dapper;  
  
namespace DapperTest.PocoInfo  
{  
    [TestFixture]  
    public class PocoInfoNotEndWithIDKeyTest  
    {  
        DapperPocoInfo dpi;  
        [SetUp]  
        public void GetDapperPocoInfo()  
        {  
            dpi = typeof(TestNotEndWithIDModel).GetPocoInfo();  
            dpi.AddKeyMap("OrderNum");  
        }  
        [Test]  
        public void TestModelKeyOnlyOneTest()  
        {  
            Assert.AreEqual(1, dpi.KeyProperties.Count());  
            Assert.AreEqual("OrderNum", dpi.KeyProperties.First().Name);  
            Assert.AreEqual(true, dpi.IsUnWriteKey());  
        }  
    }  
}  

字符串映射测试

using System.Collections.Generic;  
using NUnit.Framework;  
using Dapper;  
using System.Data;  
  
namespace DapperTest.PocoInfo  
{  
    [TestFixture]  
    public class PocoInfoStringColumnMapTest  
    {  
        KeyValuePair<DbType, int>? kvp;  
        [SetUp]  
        public void GetBasicInfo()  
        {  
            DapperPocoInfo dpi = typeof(TestEndWithIDModel).GetPocoInfo();  
            dpi.AddStringColumnMap("Name");  
            kvp = dpi.GetStringColumnMap("Name");  
        }  
        [Test]  
        public void TestModelMappedStringColumnMapTest()  
        {  
            Assert.NotNull(kvp);  
            Assert.AreEqual(DbType.AnsiString, kvp.Value.Key);  
            Assert.AreEqual(50, kvp.Value.Value);  
        }  
    }  
}

 

转 https://www.cnblogs.com/davidkam/p/3463478.html