是的呀,我以为有什么办法可以解决,看来不能这样链表查了。。 如果写成 select a1.name, (select sum(count) from a3 where no in (select no from a2 where id = a1.id )) as count , sum(a2.money) as money from a1 left join a2 on a1.id=a2.id group by a1.id ; 的结果为 但我想要 money 减去 count 的值应该怎么写呢 25-400 20-200
所以你需对 a3 加约束条件
如果写成
select a1.name,
(select sum(count) from a3 where no in (select no from a2 where id = a1.id )) as count ,
sum(a2.money) as money
from a1 left join a2 on a1.id=a2.id group by a1.id ;
的结果为 但我想要 money 减去 count 的值应该怎么写呢
25-400
20-200