1、查询表中所有重复数据,根据单个字段 name 判断
select * from student where name in (select name from student group by name having count(*) > 1)
2、查询表中重复数据的数量,根据单个字段 name 判断
select count(name) as '重复次数',name from table group by name having count(*)>1
3、查找表中多余的重复记录,根据多个字段组合 sex,name 判断
select * from student where (sex,name) in ( select sex,name from student group by sex,name having count(*) > 1)
原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
如有侵权,请联系 cloudcommunity@tencent.com 删除。
原创声明:本文系作者授权腾讯云开发者社区发表,未经许可,不得转载。
如有侵权,请联系 cloudcommunity@tencent.com 删除。