SQL重复记录查询和删除方法
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2020-12-14
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SQL重复记录查询和删除方法重复记录查询和删除方法
MYSQL 查询和删除重复记录的方法很多，下面为您介绍几种常用的 MYSQL 查询和删除重复记录的方法，希望对您查询
和删除重复数据方面能有所帮助。
SQL重复记录查询的几种方法：
1. 查找表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断
select * from people
where peopleId
in (select peopleId from people
group by peopleId
having count(peopleId) > 1)
2. 删除表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断，只留有 rowid 小的记录
delete from people
where peopleId
in (select peopleId from people
group by peopleId
having count(peopleId) > 1)
and rowid not in (
select min(rowid) from people
group by peopleId
having count(peopleId)>1)
3. 查找表中多余的重复记录（多个字段）
select * from vitae a
where (a.peopleId，a.seq)
in (select peopleId，seq from vitae
group by peopleId，seq
having count(*) > 1)
4. 删除表中多余的重复记录（多个字段），只留有 rowid 小的记录
delete from vitae a
where (a.peopleId，a.seq)
in (select peopleId，seq from vitae
group by peopleId，seq
having count(*) > 1)
and rowid not in (
select min(rowid) from vitae
group by peopleId，seq having count(*)>1)
5. 查找表中多余的重复记录（多个字段），不包含 rowid 小的记录
select * from vitae a
where (a.peopleId，a.seq)
in (select peopleId，seq from vitae
group by peopleId，seq
having count(*) > 1)
and rowid not in (
select min(rowid) from vitae
group by peopleId，seq
having count(*)>1)
以上 SQL 记录重复数据查询和删除方法，希望能够帮助你。
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