MySQL选择加入何处和何处 [英] MySQL select join where AND where

问题描述

我的数据库中有两个表:

I have two tables in my database:

产品

• id(int，主键)
• 名称(varchar)

产品标签

• product_id(int)
• tag_id(int)

我想选择具有所有给定标签的产品.我试过了:

I would like to select products having all given tags. I tried:

SELECT
    *
FROM
    Products
JOIN ProductTags ON Products.id = ProductTags.product_id
WHERE
    ProductTags.tag_id IN (1, 2, 3)
GROUP BY
    Products.id

但是它给我的产品具有任何给定的标签，而不是具有所有给定的标签.写入WHERE tag_id = 1 AND tag_id = 2是没有意义的，因为不会返回任何行.

But it gives me products having any of given tags, instead of having all given tags. Writing WHERE tag_id = 1 AND tag_id = 2 is pointless, because no rows will be returned.

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