Question

private static void ReadOrderData(string connectionString)
{
    string queryString =
        "SELECT OrderID, CustomerID FROM dbo.Orders;";

    using (SqlConnection connection =
               new SqlConnection(connectionString))
    {
        SqlCommand command =
            new SqlCommand(queryString, connection);
        connection.Open();

        SqlDataReader reader = command.ExecuteReader();

        // Call Read before accessing data.
        while (reader.Read())
        {
            Console.WriteLine(String.Format("{0}, {1}",
                reader[0], reader[1]));
        }

        // Call Close when done reading.
        reader.Close();
    }
}

How can I enhance the method above to accept any queryString? The problem is in the while. There’s a fixed # of columns I can read. I want to be able to read any number of columns so that I can populate and return a DataSet. How can I do it?

Answer 1

Use SqlDataAdapter:

private static DataSet ReadData(string connectionString, string queryString)
{
    DataSet dataSet;
    using (SqlConnection connection =
               new SqlConnection(connectionString))
    {
        connection.Open();
        SqlCommand command =
            new SqlCommand(queryString, connection);

        SqlDataAdapter adapter = new SqlDataAdapter(command);
        adapter.Fill(dataSet);
    }

    return dataSet;
}

Or something like this.