명령을 사용하여 SQL에서 DataSet 또는 DataTable을 직접 채우는 방법은 무엇입니까?

private DataSet GetDataSet(string sqlCommand, string connectionString)
{
    // Create a connection to the database
    using (var conn = new SqlConnection(connectionString))
    {
        // Create a new data adapter
        var da = new SqlDataAdapter(sqlCommand, conn);

        // Fill a new dataset with the results of the command
        var ds = new DataSet();
        da.Fill(ds);

        // Return the dataset
        return ds;
    }
}

private DataTable GetDataTable(string sqlCommand, string connectionString)
{
    // Create a connection to the database
    using (var conn = new SqlConnection(connectionString))
    {
        // Create a new data adapter
        var da = new SqlDataAdapter(sqlCommand, conn);

        // Fill a new datatable with the results of the command
        var dt = new DataTable();
        da.Fill(dt);

        // Return the datatable
        return dt;
    }
}