Помгите с запросом в mysql

[shaen]

Доброе утро!!!

Помогите с запросом в mysql

SELECT
  rc_shop_products.*, rc_shop_product_descriptions.*,
  IF(
    (SELECT rc_shop_customer_discounts.discount FROM rc_shop_customer_discounts WHERE rc_shop_customer_discounts.customer_id = 1810 AND rc_shop_customer_discounts.category_id = rc_shop_products.id AND rc_shop_customer_discounts.is_group = 0) IS NULL,
   
    (SELECT rc_shop_customer_discounts.discount FROM rc_shop_customer_discounts WHERE rc_shop_customer_discounts.customer_id = 1810 AND rc_shop_customer_discounts.category_id = rc_shop_products.id AND rc_shop_customer_discounts.is_group = 0),
    (SELECT rc_shop_customer_discounts.discount FROM rc_shop_customer_discounts WHERE rc_shop_customer_discounts.customer_id = 1810 AND rc_shop_customer_discounts.category_id = rc_shop_products.category_id AND rc_shop_customer_discounts.is_group = 1)
  ) as discount,
 
  // Дальнейшая конструкция из IF'ов не работает привожу ее для понимания что мне необходимо добиться, мне нужно проверить discount на наличие в нем значения и на основе этой проверки рассчитать скидку для товара.
 
  IF((discount IS NULL),
    (rc_shop_prices.price),
    (ROUND(CEIL((((rc_shop_prices.price / 100) * discount) + rc_shop_prices.price)*100)/100, 2))
  ) price,
 
  IF((discount IS NULL),
    (rc_shop_prices.price * rc_shop_product_descriptions.places_in)
    (ROUND(CEIL((((rc_shop_prices.price / 100) * discount) + rc_shop_prices.price)*100)/100 * rc_shop_product_descriptions.places_in, 2))
  ) p_price
 
 
FROM rc_shop_products
LEFT JOIN `rc_shop_product_descriptions` ON `rc_shop_product_descriptions`.`product_id` = `rc_shop_products`.`id`
LEFT JOIN `rc_shop_prices` ON `rc_shop_prices`.`product_id` = `rc_shop_products`.`id` AND rc_shop_prices.price_id = 47
 
WHERE rc_shop_products.category_id = 20

 

[shaen]

Кому интересно сделал так:

SELECT
  rc_shop_products.*, rc_shop_product_descriptions.*,
 @DISCOUNT :=  IF(
    (SELECT rc_shop_customer_discounts.discount FROM rc_shop_customer_discounts WHERE rc_shop_customer_discounts.customer_id = 1810 AND rc_shop_customer_discounts.category_id = rc_shop_products.id AND rc_shop_customer_discounts.is_group = 0) IS NULL,
 
    (SELECT rc_shop_customer_discounts.discount FROM rc_shop_customer_discounts WHERE rc_shop_customer_discounts.customer_id = 1810 AND rc_shop_customer_discounts.category_id = rc_shop_products.id AND rc_shop_customer_discounts.is_group = 0),
    (SELECT rc_shop_customer_discounts.discount FROM rc_shop_customer_discounts WHERE rc_shop_customer_discounts.customer_id = 1810 AND rc_shop_customer_discounts.category_id = rc_shop_products.category_id AND rc_shop_customer_discounts.is_group = 1)
  ) as discount,
 
  IF((@DISCOUNT IS NULL),
    (rc_shop_prices.price),
    (ROUND(CEIL((((rc_shop_prices.price / 100) * @DISCOUNT) + rc_shop_prices.price)*100)/100, 2))
  ) as price,
 
  IF((@DISCOUNT IS NULL),
    (rc_shop_prices.price * rc_shop_product_descriptions.places_in),
    (ROUND(CEIL((((rc_shop_prices.price / 100) * @DISCOUNT) + rc_shop_prices.price)*100)/100 * rc_shop_product_descriptions.places_in, 2))
  ) as p_price
 
 
FROM rc_shop_products
LEFT JOIN `rc_shop_product_descriptions` ON `rc_shop_product_descriptions`.`product_id` = `rc_shop_products`.`id`
LEFT JOIN `rc_shop_prices` ON `rc_shop_prices`.`product_id` = `rc_shop_products`.`id` AND rc_shop_prices.price_id = 47
 
WHERE rc_shop_products.category_id = 20