简易orm 主要是为了旧平台查询方便
直接新建个文件即可
ExLogic.cs
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
}
使用
var entity=ExLogic.Get<DeviceNbIotMapping>(s => s.id == id);//返回单个
//需要返回列表等功能自行扩展
咩咩咩
