MySQL 如何在此查询中创建选择子查询

Question

我究竟如何能够利用子查询将这两个查询转换为一个查询？

select p.id, m.display_name, m.updated_at, group_concat(meta.value) as value, p.path
from metadata_custom meta
right join page as p on p.id = meta.page_id
inner join metadata m on p.metadata_id = m.id
where p.path like '/history/%' and p.path not like '/history/%/%'
group by p.id

SELECT * FROM cascade_publish.folder
where path like '/history/%' and path not like '/history/%/%'

我见过的大多数子查询都使用 WHERE IN....最好我应该能够将第二个查询放在第一个查询中的某个位置，我该怎么做？

Answer 1

一种方法是使用子查询作为选择字段:

SELECT p.id
 ( SELECT folder FROM cascade_publish
   where path like '/history/%' and path not like '/history/%/%') as publish_folder
FROM ...