在没有主关键子的情况下 用于查询一张表里面有多少条重复记录

select newsid ,title from news where title in (select title from news t where classname3='A-' group by title having count(title) >= 2)



select sys_zdm from jjpc629

         group by sys_zdm having count(sys_zdm) >= 2




select * from jjpc629

         group by sys_zdm having count(sys_zdm) >= 2

这个语句的意思就是查询在 jjpc629 表里面sys_zdm字段多余 2 条的的重复的记录.



select * from jjpc629 
        group by sys_zdm having count(sys_zdm) >= 1

unio
 
select * from jjpc629 
        group by sys_zdm having count(sys_zdm) >= 5


这个语句的意思是查询 多余 1条 与多余 5 条的组成一个新表