Question

I’m trying to fill DataSet which contains 2 tables with one to many relationship.
I’m using DataReader to achieve this :

    public DataSet SelectOne(int id)
    {
        DataSet result = new DataSet();
        using (DbCommand command = Connection.CreateCommand())
        {
            command.CommandText = "select * from table1";

            var param = ParametersBuilder.CreateByKey(command, "ID", id, null);
            command.Parameters.Add(param);

            Connection.Open();
            using (DbDataReader reader = command.ExecuteReader())
            {
                result.MainTable.Load(reader);
            }
            Connection.Close();
        }
        return result;
    }

But I’ve got only one table filled up. How do I achieve my goal – fill both tables?

I would like to use DataReader instead DataAdapter, if it possible.

Answer 1

If you are issuing a single command with several select statements, you might use NextResult method to move to next resultset within the datareader: http://msdn.microsoft.com/en-us/library/system.data.idatareader.nextresult.aspx

I show how it could look bellow:

public DataSet SelectOne(int id)
{
    DataSet result = new DataSet();
    using (DbCommand command = Connection.CreateCommand())
    {
        command.CommandText = @"
select * from table1
select * from table2
        ";

        var param = ParametersBuilder.CreateByKey(command, "ID", id, null);
        command.Parameters.Add(param);

        Connection.Open();
        using (DbDataReader reader = command.ExecuteReader())
        {
            result.MainTable.Load(reader);
            reader.NextResult();
            result.SecondTable.Load(reader);
            // ...
        }
        Connection.Close();
    }
    return result;
}