查询及删除重复记录

Posted 2023-03-23

参考技术A

　　(一) 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) > ) 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最小的记录 delete from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > ) and rowid not in (select min(rowid) from people group by peopleId having count(peopleId )> ) 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(*) > ) 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 vitae a where (a peopleId a seq) in (select peopleId seq from vitae group by peopleId seq having count(*) > ) and rowid not in (select min(rowid) from vitae group by peopleId seq having count(*)> )

　　 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 vitae a where (a peopleId a seq) in (select peopleId seq from vitae group by peopleId seq having count(*) > ) and rowid not in (select min(rowid) from vitae group by peopleId seq having count(*)> ) (二) 比方说 在A表中存在一个字段“name” 而且不同记录之间的“name”值有可能会相同 现在就是需要查询出在该表中的各记录之间 “name”值存在重复的项 Select Name Count(*) From A Group By Name Having Count(*) > 如果还查性别也相同大则如下: Select Name * Count(*) From A Group By Name * Having Count(*) >

lishixinzhi/Article/program/mysql/201311/29563

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（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最小的记录 

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最小的记录 

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最小的记录 

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)

 

 

delete from 表名 where 字段ID in (select * from (select max(字段ID) from 表名 group by 重复的字段 having count(重复的字段) > 1) as b);