MYSQL 查询变体价格范围内没有重复的产品

Question

我正在尝试查询我的产品 table，以便我查询 returns 某个变体价格范围内的产品集 -- 产品有很多变体，变体属于产品。我有以下正在运行的查询，但它非常慢 -- 查询需要 1.66 秒。

SELECT colortags.tag, products.*, (SELECT variants.price FROM variants WHERE variants.product_id = products.product_id LIMIT 1) price, collects.position 
FROM products
INNER JOIN wp_wps_collects collects 
ON products.product_id = collects.product_id 
AND collects.collection_id = 123456788
INNER JOIN wp_wps_tags colortags 
ON colortags.product_id = collects.product_id 
AND (colortags.tag = 'black' OR colortags.tag = 'nav') 
INNER JOIN wp_wps_tags styletags 
ON styletags.product_id = collects.product_id 
AND (styletags.tag = 'purses')
WHERE (SELECT variants.price FROM variants WHERE variants.product_id = products.product_id AND variants.price >= 200 AND variants.price < 300 LIMIT 1) > 0
AND (SELECT variants.price FROM variants WHERE variants.product_id = products.product_id AND variants.price >= 200 AND variants.price < 300 LIMIT 1) <> 0

在 WHERE 语句中，我尝试只检查 SELECT 语句中子查询创建的 price 值，但是 MYSQL 告诉我 price 未定义。这是 SQL:

SELECT colortags.tag, products.*, (SELECT variants.price FROM wp_wps_variants variants WHERE variants.product_id = products.product_id LIMIT 1) price, collects.position 
FROM wp_wps_products products
INNER JOIN wp_wps_collects collects 
ON products.product_id = collects.product_id 
AND collects.collection_id = 98515058801
INNER JOIN wp_wps_tags colortags 
ON colortags.product_id = collects.product_id 
AND (colortags.tag = 'color:generic-black' OR colortags.tag = 'color:navy') 
INNER JOIN wp_wps_tags styletags 
ON styletags.product_id = collects.product_id 
AND (styletags.tag = 'style:totes')
WHERE price >= 200 
AND price < 300

这是我从上面 SQL:

得到的错误消息

Unknown column 'price' in 'where clause'

我也曾尝试在 variants table 上使用一系列连接，但随后返回了重复的产品。这是 SQL

SELECT colortags.tag, products.*, (SELECT variants.price FROM variants WHERE variants.product_id = products.product_id LIMIT 1) price, collects.position 
FROM products
INNER JOIN collects 
ON products.product_id = collects.product_id 
AND collects.collection_id = 1234566
INNER JOIN colortags 
ON colortags.product_id = collects.product_id 
AND (colortags.tag = 'black' OR colortags.tag = 'navy') 
INNER JOIN styletags 
ON styletags.product_id = collects.product_id 
AND (styletags.tag = 'purses')
INNER JOIN variants
ON variants.product_id = products.product_id
AND variants.price >= 200 
AND variants.price < 300
AND variants.price > 0
AND variants.price <> 0

我想要的是从第一个 SQL 语句获得的没有性能影响的查询结果。我想我可以在变体 table 上写 SQL 和 INNER JOIN 来过滤掉不正确价格的变体而不会得到重复的产品，但我无法确定如何。

有谁知道我如何在此处编写 SQL，这样我就可以在特定变体价格范围内查询产品，而不会返回重复产品并且不会严重影响性能？

Answer 1

如果将查询封装在另一个查询中，则可以在 where 子句中使用 price

SELECT * from (
    SELECT colortags.tag, products.*, (SELECT variants.price FROM variants WHERE variants.product_id = products.product_id LIMIT 1) price, collects.position 
    FROM products
    INNER JOIN wp_wps_collects collects 
    ON products.product_id = collects.product_id 
    AND collects.collection_id = 123456788
    INNER JOIN wp_wps_tags colortags 
    ON colortags.product_id = collects.product_id 
    AND (colortags.tag = 'black' OR colortags.tag = 'nav') 
    INNER JOIN wp_wps_tags styletags 
    ON styletags.product_id = collects.product_id 
    AND (styletags.tag = 'purses')
    WHERE (SELECT variants.price FROM variants WHERE variants.product_id = products.product_id AND variants.price >= 200 AND variants.price < 300 LIMIT 1) > 0
) t 
WHERE t.price >= 200 and t.price < 300

Answer 2

你正在做一个半连接，这意味着你想做一个连接，但你只想要一行结果，即使有多个匹配。

执行此操作的一种方法是连接到派生的 table，它在子查询中使用 GROUP BY 将每个 product_id.

的变体减少到一行

SELECT colortags.tag, products.*, prices.price, collects.position 
FROM products
INNER JOIN wp_wps_collects collects 
  ON products.product_id = collects.product_id 
  AND collects.collection_id = 123456788
INNER JOIN wp_wps_tags colortags 
  ON colortags.product_id = collects.product_id 
  AND (colortags.tag = 'black' OR colortags.tag = 'nav') 
INNER JOIN wp_wps_tags styletags 
  ON styletags.product_id = collects.product_id 
  AND (styletags.tag = 'purses')
INNER JOIN (
  SELECT v.product_id, MIN(v.price) AS price FROM variants v
  INNER JOIN wp_wps_collects c ON v.product_id = c.product_id
  WHERE c.collection_id = 123456788
  GROUP BY product_id ORDER BY NULL
) prices
  ON products.product_id = prices.product_id

我以为您会对每件产品的最低价格感兴趣。您也可以在派生的 table.

中使用 MAX()

我不得不将连接复制到 wp_wps_collects，因此派生的 table 将仅限于与您正在查询的集合相关的产品。否则，如果您有数百万个产品，派生的 table 会变得如此之大，以至于会产生不同的性能问题。

MYSQL 查询变体价格范围内没有重复的产品

MYSQL query on products within variant price range without duplicates

mysql

semi-join