SQL多对多选择
SQL多对多选择
提问于 2010-08-15 16:01:37
category_product
---------------
id_category
id_product
product
---------------
id_product
id_manufacturer
manufacturer
---------------
id_manufacturer
name当id_category等于某个值时，我如何创建一个SQL查询，以便它选择制造商中的所有名称？
回答 5
Stack Overflow用户
回答已采纳
发布于 2010-08-15 16:05:39
这是一个简单的表的内部连接：
SELECT m.name, cp.id_category
FROM manufacturer as m
INNER JOIN product as p
ON m.id_manufacturer = p.id_manufacturer
INNER JOIN category_product as cp
ON p.id_product = cp.id_product
WHERE cp.id_category = 'some value'Stack Overflow用户
发布于 2010-08-15 16:09:29
没有连接的查询将如下所示：
SELECT m.name
FROM manufacturer as m, product as p, category_product as cp
WHERE cp.id_category = <your value>
AND cp.id_product = p.id_product
AND p.id_manufacturer = m.id_manufacturer Stack Overflow用户
发布于 2010-08-15 16:14:09
Select M.name
From manufacturer M
Where M.id_manufacturer in ( Select P.id_manufacturer
From product P
Where P.id_product in ( Select C.id_product
From category_product C
Where C.id_category = ?))页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/3486644
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