Mysql 内部连接取决于行

我有一个表，其中包含，例如：

post_id | title
   1       im in Guadalajara and Zapopan
   2       im just in Guadalajara but not in Zapopan

和表元键

post_id | meta_key
  1         Guadalajara
  1         Zapopan
  2         Guadalajara

我需要同时获得瓜达拉哈拉和扎波潘的帖子，我意识到如果我与or进行内部连接，将会同时获得这两个帖子

在本例中，我希望构造一个抛出post 1（仅1）的查询

---

谢谢

一种方法是使用双连接：

select
  *
from
  posts p
inner join meta_keys mk1 on p.post_id = mk1.post_id
inner join meta_keys mk2 on p.post_id = mk2.post_id
where
  mk1.meta_key = 'Guadalajara' and
  mk2.meta_key = 'Zapopan'
;

---

以下内容将为您提供两个文件中的

post\u id

s

select post_id
  from meta_keys
 where meta_key in ('Guadalajara','Zapopan')
 group by post_id
having count(*) = 2

然后，您可以将其加入到

帖子中

以获得实际帖子：

select p.*
  from posts as p
  join ( select post_id
           from meta_keys
          where meta_key in ('Guadalajara','Zapopan')
          group by post_id
         having count(*) = 2 ) as m
    on p.post_id = m.post_id