SQL-删除重复数据

查询及删除重复记录的SQL语句

1、查找表中多余的重复记录，重复记录是根据单个字段（Id）来判断

select * from 表 where Id in (select Id from 表 group byId having count(Id) > 1)

2、删除表中多余的重复记录，重复记录是根据单个字段（Id）来判断，只留有rowid最小的记录

DELETE from 表 
WHERE (id) IN 
( SELECT id FROM 表 GROUP BY id HAVING COUNT(id) > 1) 
AND ROWID NOT IN (SELECT MIN(ROWID) 
FROM 表 GROUP BY id HAVING COUNT(*) > 1);

3、查找表中多余的重复记录（多个字段）

select * from 表 a where (a.Id,a.seq) in(select Id,seq from 表 group by Id,seq having count(*) > 1)

4、删除表中多余的重复记录（多个字段），只留有rowid最小的记录

delete from 表 a 
where (a.Id,a.seq) in (select Id,seq 
from 表 group by Id,seq having count( * ) > 1) 
and 
rowid not in (select min(rowid) 
from 表 group by Id,seq having count( * )>1)

5、查找表中多余的重复记录（多个字段），不包含rowid最小的记录

select * from 表 a 
where (a.Id,a.seq) in 
(select Id,seq from 表 group by Id,seq having count( * ) > 1) 
and 
rowid not in (select min(rowid) 
from 表 group by Id,seq having count( * )>1)

标签：group,删除,seq,重复,rowid,SQL,重复记录,Id,select
来源： https://www.cnblogs.com/wyid/p/11260835.html