select id,(select cladd_id,count(*) from bb where bb.cladd_id=aa.id group by claddd_id)as class_id from aa 没测试。楼主可是试试
select id,t.c from AA left join (select class_id as id,count(*) as c from BB group by class_id ) t on AA.id=t.id
你的问题提的不怎么样,哈答案一 liuyann(liuyann) select class_id,count(*) from BB group by class_id答案2 select * from AA a order by (select count(*) from bb b where aa.id = bb.class_id)
select aa.id , count(1) as 'class_id(统计)' from aa , bb where aa.id = bb.class_id
没测试。楼主可是试试
(select class_id as id,count(*) as c
from BB
group by class_id
) t
on AA.id=t.id
liuyann(liuyann)
select class_id,count(*)
from BB
group by class_id答案2
select * from AA a
order by (select count(*) from bb b where aa.id = bb.class_id)
select aa.id ,
count(1) as 'class_id(统计)'
from aa ,
bb
where aa.id = bb.class_id