public string GetCommandText(Expression expression)
{
var parser = new QueryExpressionParser(_connection);
parser.Parse(expression);
return(parser.ToSql());
}
public TResult Execute <TResult>(Expression expression)
{
var parser = new QueryExpressionParser(_connection);
parser.Parse(expression);
Type type = typeof(TResult);
if (expression.NodeType == ExpressionType.Call && type.IsValueType)
{
var callMethod = ((MethodCallExpression)expression).Method;
switch (callMethod.Name)
{
case "Any":
//case "Average":
//case "Sum":
case "Count":
var returnMethod = typeof(SqlMapper).GetMethods(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Static).FirstOrDefault(x => x.Name == "ExecuteScalar" && x.IsGenericMethodDefinition).MakeGenericMethod(type);
var param0 = Expression.Parameter(typeof(IDbConnection));
var param1 = Expression.Parameter(typeof(string));
var param2 = Expression.Parameter(typeof(object));
var param3 = Expression.Parameter(typeof(IDbTransaction));
var param4 = Expression.Parameter(typeof(int?));
var param5 = Expression.Parameter(typeof(CommandType?));
var source = Expression.Call(returnMethod, param0, param1, param2, param3, param4, param5);
return(Expression.Lambda <Func <IDbConnection, string, object, IDbTransaction, int?, CommandType?, TResult> >(source, param0, param1, param2, param3, param4, param5).Compile()(_connection, parser.ToSql(), parser.Parameters, null, null, null));
default:
throw new Exception("not supported yet");
}
}
else
{
MethodInfo method;
//var isAnonymous = false;
//if (!isAnonymous)
//{
method = typeof(SqlMapper).GetMethods(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Static).FirstOrDefault(x => x.Name == "Query" && x.IsGenericMethodDefinition).MakeGenericMethod(type.IsGenericType ? type.GetGenericArguments() : new[] { type });
//}
//else
//{
// method = typeof(SqlMapper).GetMethods(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Static).FirstOrDefault(x => x.Name == "Query" && !x.IsGenericMethodDefinition);
//}
var param0 = Expression.Parameter(typeof(IDbConnection));
var param1 = Expression.Parameter(typeof(string));
var param2 = Expression.Parameter(typeof(object));
var param3 = Expression.Parameter(typeof(IDbTransaction));
var param4 = Expression.Parameter(typeof(bool));
var param5 = Expression.Parameter(typeof(int?));
var param6 = Expression.Parameter(typeof(CommandType?));
var source = Expression.Call(method, param0, param1, param2, param3, param4, param5, param6);
if (type.IsGenericType)
{
return(Expression.Lambda <Func <IDbConnection, string, object, IDbTransaction, bool, int?, CommandType?, TResult> >(source, param0, param1, param2, param3, param4, param5, param6).Compile()(_connection, parser.ToSql(), parser.Parameters, null, true, null, null));
}
else
{
var results = Expression.Lambda <Func <IDbConnection, string, object, IDbTransaction, bool, int?, CommandType?, IEnumerable <TResult> > >(source, param0, param1, param2, param3, param4, param5, param6).Compile()(_connection, parser.ToSql(), parser.Parameters, null, true, null, null);
var callMethod = ((MethodCallExpression)expression).Method;
switch (callMethod.Name)
{
case "First":
return(results.First());
case "FirstOrDefault":
return(results.FirstOrDefault());
case "Last":
return(results.Last());
case "LastOrDefault":
return(results.LastOrDefault());
default:
throw new Exception("not supported yet");
}
}
}
}
