SQL语句

描述：exhibitiononline表主键exhiid， exhibitor表有外键 exhid，对应表 exhibitiononline的主键exhiid;

exhibitiononline表---------> 一对多 <------------- exhibitor表

功能：查询出 exhibitiononline表中，exhiid存在于表 exhibitor中的所有数据，并根据 exhibitor表的exhid的数量排序

select * from exhibitiononline join

(select exhid,count(exhid) as s from exhibitor group by exhid) as t

on exhibitiononline.exhiid=t.exhid

order by t.s desc

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