Select a.*,x.cn as 借阅次数
from a inner Join
( Select 书的编号,count(1) as cn
from b
group by 书的编号) as x on a.书的编号=x.书的编号
order by x.cn desc
from a inner Join
( Select 书的编号,count(1) as cn
from b
group by 书的编号) as x on a.书的编号=x.书的编号
order by x.cn desc
调试欢乐多
a.bookid ,count(b.*) as cs
from
a left join b on a.bookid = b.bookid
group by
a.bookid
order by 2
from a,b
where a.bookid=b.bookid
group by a.bookid,a.名字
group by sum(b.bookid) desc
from a inner Join
( Select bookid,count(1) as cs
from b
group by bookid) as x on a.bookid=x.bookid
order by x.cs desc