简易orm 主要是为了旧平台查询方便

直接新建个文件即可

1	`ExLogic.cs`

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    public class ExLogic
    {
 
 
        public static int Execute(string sqlCommand, string dbConnection = "WebDb")
        {
            Database db = DatabaseFactory.CreateDatabase(dbConnection);
            DbCommand dbCommand = db.GetSqlStringCommand(sqlCommand);
            try
            {
                return Convert.ToInt32(db.ExecuteScalar(dbCommand));
            }
            catch (Exception ex)
            {
                Logging.WriteLog(ex);
                throw ex;
            }
 
        }
 
 
 
        /// <summary>
        /// 获取对象
        /// </summary>
        /// <typeparam name="T">对象</typeparam>
        /// <param name="where">非必填</param>
        /// <returns></returns>
        public static T Get<T>(Expression<Func<T, bool>> where = null, string dbConnection = "WebDb") where T : class, new()
        {
            var whereSql = LambdaToSqlHelper.GetWhereSql(where);
 
            Database db = DatabaseFactory.CreateDatabase(dbConnection);
            string sqlCommand = $"SELECT * FROM {typeof(T).Name} WHERE " + (where == null ? "1==1" : whereSql);
            DbCommand dbCommand = db.GetSqlStringCommand(sqlCommand);
            try
            {
                var res = new T();
                using (IDataReader dr = db.ExecuteReader(dbCommand))
                {
                    if (dr.Read())
                    {
                        var typeoft = typeof(T);
                        var proper = typeoft.GetProperties();
                        foreach (var item in proper)
                        {
                            if (item.PropertyType == typeof(int))
                                item.SetValue(res, DataReaderHelper.GetInt32(dr, item.Name), null);
                            else if (item.PropertyType == typeof(long))
                                item.SetValue(res, DataReaderHelper.GetInt64(dr, item.Name), null);
                            else if (item.PropertyType == typeof(string))
                                item.SetValue(res, DataReaderHelper.GetString(dr, item.Name), null);
                            else if (item.PropertyType == typeof(bool))
                                item.SetValue(res, DataReaderHelper.GetBoolean(dr, item.Name), null);
                            else if (item.PropertyType == typeof(decimal))
                                item.SetValue(res, DataReaderHelper.GetDecimal(dr, item.Name), null);
                            else if (item.PropertyType == typeof(double))
                                item.SetValue(res, DataReaderHelper.GetDouble(dr, item.Name), null);
                            else if (item.PropertyType == typeof(DateTime))
                                item.SetValue(res, DataReaderHelper.GetDateTime(dr, item.Name), null);
                        }
                    }
                }
                return res;
            }
            catch (Exception ex)
            {
                throw;
            }
        }
 
 
           
 
 
 
    }
 
/// <summary>
        /// 这部分代码网上可找,自行百度 ,我有稍作修改
        /// </summary>
    public static class LambdaToSqlHelper
    {
 
 
        #region 基础方法
 
        #region 获取条件语句方法
 
        public static string GetWhereSql<T>(Expression<Func<T, bool>> func) where T : class
        {
            string res;
            if (func.Body is BinaryExpression)
            {
                //起始参数
 
                BinaryExpression be = ((BinaryExpression)func.Body);
                res = BinarExpressionProvider(be.Left, be.Right, be.NodeType);
            }
            else if (func.Body is MethodCallExpression)
            {
                MethodCallExpression be = ((MethodCallExpression)func.Body);
                res = ExpressionRouter(func.Body);
            }
            else
            {
                res = " ";
            }
 
            return res;
        }
 
        #endregion 获取条件语句方法
 
 
 
        #region 获取排序语句 order by
 
        public static string GetOrderSql<T>(Expression<Func<T, object>> exp) where T : class
        {
            var res = "";
            if (exp.Body is UnaryExpression)
            {
                UnaryExpression ue = ((UnaryExpression)exp.Body);
                res = "order by `" + ExpressionRouter(ue.Operand).ToLower() + "`";
            }
            else
            {
                MemberExpression order = ((MemberExpression)exp.Body);
                res = "order by `" + order.Member.Name.ToLower() + "`";
            }
            return res;
        }
 
        #endregion 获取排序语句 order by
 
 
 
        #endregion 基础方法
 
        #region 底层
 
        public static bool In<T>(this T obj, T[] array)
        {
            return true;
        }
 
        public static bool NotIn<T>(this T obj, T[] array)
        {
            return true;
        }
 
        public static bool Like(this string str, string likeStr)
        {
            return true;
        }
 
        public static bool NotLike(this string str, string likeStr)
        {
            return true;
        }
 
        private static string GetValueStringByType(object oj)
        {
            if (oj == null)
            {
                return "null";
            }
            else if (oj is ValueType)
            {
                return oj.ToString();
            }
            else if (oj is string || oj is DateTime || oj is char)
            {
                return string.Format("'{0}'", oj.ToString());
            }
            else
            {
                return string.Format("'{0}'", oj.ToString());
            }
        }
 
        private static string BinarExpressionProvider(Expression left, Expression right, ExpressionType type)
        {
            var sb = string.Empty;
            //先处理左边
            string reLeftStr = ExpressionRouter(left);
            sb += reLeftStr;
 
            sb += ExpressionTypeCast(type);
 
            //再处理右边
            string tmpStr = ExpressionRouter(right);
            if (tmpStr == "null")
            {
                if (sb.EndsWith(" ="))
                {
                    sb = sb.Substring(0, sb.Length - 2) + " is null";
                }
                else if (sb.EndsWith("<>"))
                {
                    sb = sb.Substring(0, sb.Length - 2) + " is not null";
                }
            }
            else
            {
                //添加参数
                sb += tmpStr;
            }
 
            return sb;
        }
 
        private static string ExpressionRouter(Expression exp)
        {
            string sb = string.Empty;
 
            if (exp is BinaryExpression)
            {
                BinaryExpression be = ((BinaryExpression)exp);
                return BinarExpressionProvider(be.Left, be.Right, be.NodeType);
            }
            else if (exp is MemberExpression)
            {
                MemberExpression me = ((MemberExpression)exp);
                if (!exp.ToString().StartsWith("value"))
                {
                    return me.Member.Name;
                }
                else
                {
                    var result = Expression.Lambda(exp).Compile().DynamicInvoke();
                    if (result == null)
                    {
                        return "null";
                    }
                    else
                    {
                        return result.ToString();
                    }
                }
            }
            else if (exp is NewArrayExpression)
            {
                NewArrayExpression ae = ((NewArrayExpression)exp);
                StringBuilder tmpstr = new StringBuilder();
                foreach (Expression ex in ae.Expressions)
                {
                    tmpstr.Append(ExpressionRouter(ex));
                    tmpstr.Append(",");
                }
                //添加参数
 
                return tmpstr.ToString(0, tmpstr.Length - 1);
            }
            else if (exp is MethodCallExpression)
            {
                MethodCallExpression mce = (MethodCallExpression)exp;
                string par = ExpressionRouter(mce.Arguments[0]);
                if (mce.Method.Name == "Like")
                {
                    //添加参数用
                    return string.Format("({0} like {1})", par, ExpressionRouter(mce.Arguments[1]));
                }
                else if (mce.Method.Name == "NotLike")
                {
                    //添加参数用
                    return string.Format("({0} Not like {1})", par, ExpressionRouter(mce.Arguments[1]));
                }
                else if (mce.Method.Name == "In")
                {
                    //添加参数用
                    return string.Format("{0} In ({1})", par, ExpressionRouter(mce.Arguments[1]));
                }
                else if (mce.Method.Name == "NotIn")
                {
                    //添加参数用
                    return string.Format("{0} Not In ({1})", par, ExpressionRouter(mce.Arguments[1]));
                }
            }
            else if (exp is ConstantExpression)
            {
                ConstantExpression ce = ((ConstantExpression)exp);
                if (ce.Value == null)
                {
                    return "null";
                }
                else
                {
 
                    return $"'{ce.Value.ToString()}'";
 
                }
 
                //对数值进行参数附加
            }
            else if (exp is UnaryExpression)
            {
                UnaryExpression ue = ((UnaryExpression)exp);
 
                return ExpressionRouter(ue.Operand);
            }
            return null;
        }
 
        private static string ExpressionTypeCast(ExpressionType type)
        {
            switch (type)
            {
                case ExpressionType.And:
                case ExpressionType.AndAlso:
                    return " AND ";
 
                case ExpressionType.Equal:
                    return " =";
 
                case ExpressionType.GreaterThan:
                    return " >";
 
                case ExpressionType.GreaterThanOrEqual:
                    return ">=";
 
                case ExpressionType.LessThan:
                    return "<";
 
                case ExpressionType.LessThanOrEqual:
                    return "<=";
 
                case ExpressionType.NotEqual:
                    return "<>";
 
                case ExpressionType.Or:
                case ExpressionType.OrElse:
                    return " Or ";
 
                case ExpressionType.Add:
                case ExpressionType.AddChecked:
                    return "+";
 
                case ExpressionType.Subtract:
                case ExpressionType.SubtractChecked:
                    return "-";
 
                case ExpressionType.Divide:
                    return "/";
 
                case ExpressionType.Multiply:
                case ExpressionType.MultiplyChecked:
                    return "*";
 
                default:
                    return null;
            }
        }
 
        #endregion 底层
    }