13问答网 > sql select id from a where id=(select id from b where id=(select id from c where name=✀aaaaa✀))

sql select id from a where id=(select id from b where id=(select id from c where name=✀aaaaa✀))

2025-04-28 07:16:03

推荐回答（3个）

回答1：

如果A表中id是主键，只想返回一个结果，用inner join 的话，结果可能是多个行，不符合要求
用exists
sql select a.id from a
where exists
（
select 1 from b
inner join c
on b.id=c.id
where c.name='aaaaa'
and a.id = b.id
）

回答2：

sql select id from a where id=(select id from b where id=(select id from c where name='aaaaa'))
改成inner join
sql select a.id from a
inner join b
on a.id=b.id
inner join c
on b.id=c.id
where c.name='aaaaa'

回答3：

这肯定要用关联查询吧，没这样写过，前两个=都换成in呢