public TResult Min <TResult>(Expression <Func <T, TResult> > minExpression)
{
SqlProvider.FormatMin(minExpression);
return(DbCon.QuerySingleOrDefault <TResult>(SqlProvider.SqlString, SqlProvider.Params, dbTransaction));
}
/// <summary>
/// 反射执行需要指向T类型的函数
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="sqlProvider"></param>
/// <param name="methodName"></param>
public void FormatSend <T>(QuerySet <T> querySet, string methodName)
{
SqlProvider sqlProvider = querySet.SqlProvider;
//写入重新生成后的条件
if (WhereExpression != null && WhereExpression.Any())
{
querySet.WhereExpressionList.AddRange(WhereExpression);
}
//因为表达式的原因，递归获取连表默认会倒序
if (sqlProvider.JoinList.Any())
{
sqlProvider.JoinList.Reverse();
}
switch (methodName)
{
case "Count":
{
sqlProvider.FormatCount();
}
break;
case "Sum":
{
var lambda = this.expression.Arguments[0].GetLambdaExpression();
sqlProvider.FormatSum(lambda);
}
break;
case "Min":
{
var lambda = this.expression.Arguments[0].GetLambdaExpression();
sqlProvider.FormatMin(lambda);
}
break;
case "Max":
{
var lambda = this.expression.Arguments[0].GetLambdaExpression();
sqlProvider.FormatMax(lambda);
}
break;
case "Get":
{
LambdaExpression lambda = default(LambdaExpression);
if (this.expression.Arguments.Count == 1)
{
lambda = this.expression.Arguments[0].GetLambdaExpression();
this.ReturnType = lambda.ReturnType;
}
else if (this.expression.Arguments.Count == 0) //无自定义列表返回
{
lambda = null;
this.ReturnType = this.expression.Method.ReturnType;
}
else
{
//带if判断
if (this.expression.Arguments[0].ToConvertAndGetValue().Equals(true))
{
lambda = this.expression.Arguments[1].GetLambdaExpression();
}
else
{
lambda = this.expression.Arguments[2].GetLambdaExpression();
}
this.ReturnType = lambda.ReturnType;
}
sqlProvider.Context.Set.SelectExpression = lambda;
sqlProvider.FormatGet <T>();
}
break;
case "ToList":
{
LambdaExpression lambda = default(LambdaExpression);
if (this.expression.Arguments.Count == 1)
{
lambda = this.expression.Arguments[0].GetLambdaExpression();
this.ReturnType = lambda.ReturnType;
}
else if (this.expression.Arguments.Count == 0) //无自定义列表返回
{
lambda = null;
this.ReturnType = this.expression.Method.ReturnType.GenericTypeArguments[0];
}
else
{
//带if判断
if (this.expression.Arguments[0].ToConvertAndGetValue().Equals(true))
{
lambda = this.expression.Arguments[1].GetLambdaExpression();
}
else
{
lambda = this.expression.Arguments[2].GetLambdaExpression();
}
this.ReturnType = lambda.ReturnType;
}
sqlProvider.Context.Set.SelectExpression = lambda;
sqlProvider.FormatToList <T>();
}
break;
default:
throw new DapperExtensionException("Kogel.Dapper.Extension中子查询不支持的扩展函数");
}
//得到解析的sql和param对象
string sql = sqlProvider.SqlString;
var param = ToSubqueryParam(sqlProvider.Params, ref sql);
_sqlCmd.Append(sql);
this.Param.AddDynamicParams(param);
}