PetaPoco Stored Procedure Return Value

ReturnVal

var sql = new Sql().Append("declare @@result int")
    .Append("exec GetData @userId, @date", 
        new {userId = userId, @date = DateTime.Now})
    .Append("select @@result);

var ret = Database.ExecuteScalar<int>(sql);

When i try this i am getting null......Need help pls

var sql = new Sql().Append("declare @@result int")
    .Append("exec @@result = GetData @userId, @date", 
        new {userId = userId, @date = DateTime.Now})
    .Append("select @@result");

var ret = Database.ExecuteScalar<int>(sql);