Preparser

  call sql_prepare(dbh, """
    SELECT
            test_invoice.id,
            test_customer.company_name,
            sum(test_invoice_line.items * test_invoice_line.price) AS total,
            'AB12' as words
    FROM
            test_invoice,
            test_customer,
            test_invoice_line
    WHERE
            test_customer.id = test_invoice.test_customer_id
            AND test_invoice.id = test_invoice_line.test_invoice_id
    GROUP  BY
            test_invoice.id, test_customer.company_name
    ORDER BY
            test_customer.company_name
  """)