SELECT
    GROUP_CONCAT(
        CONCAT(
            dtb_order.order_id,
            ',',
            dtb_order_detail.product_code,
            ',',
            dtb_order_detail.product_name,
            ',',
            CASE
                WHEN
                    dtb_order_detail.product_code = '003' or dtb_order_detail.product_code = '006'
                THEN
                    dtb_order_detail.quantity * 2
                ELSE
                    dtb_order_detail.quantity 
            END
        ) ORDER BY dtb_order_detail.order_detail_id 
         DESC SEPARATOR ','
    )
FROM
    dtb_order INNER JOIN 
    dtb_order_detail ON dtb_order.order_id = dtb_order_detail.order_id 
GROUP BY dtb_order.order_id