老师教我优化这个SQL语句 Select tb1.id,tb1.name,isnull((select name from tb5 where id=tb1.id),’’)
from tb1,tb2,tb3
where tb1.id=tb2.pid and tb1.id=tb3.pid and tb1.id not in (select id from tb4)
group by tb1.id,tb1.name我不会写 希望各位大虾帮帮忙
from tb1,tb2,tb3
where tb1.id=tb2.pid and tb1.id=tb3.pid and tb1.id not in (select id from tb4)
group by tb1.id,tb1.name我不会写 希望各位大虾帮帮忙
from tb1,tb5
where tb1.id=tb5.id and tb1.id not in (select id from tb4)
group by tb1.id不知道是不是你要的?
Select tb1.id,tb1.name,isnull((select name from tb5 where id=tb1.id),’’)
from tb1 inner join tb1.id=tb2.pid
inner join tb1.id=tb3.pid on tb1.id not in (select id from tb4)
group by tb1.id,tb1.name
试试
from tb1 a inner join tb2 b on a.id=b.pid
inner join tb3 c on a.id=c.pid
where a.id not in (select id from tb4)
group by a.id,a.name
from tb1 a inner join tb2 b on a.id=b.pid
inner join tb3 c on a.id=c.pid
inner join tb4 d on a.id<>d.id
left join tb5 e on a.id=e.id
group by a.id, a.name
from tb1 left join tb2 on tb1.id=tb2.pid
left join tb3 on tb1.id=tb3.pid
left join tb5 on on tb1.id=tb5.pid
where tb1.id not in (select id from tb4)
group by tb1.id,tb1.name