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織夢網站MYSQL查詢重復記錄的方法

POST TIME:2020-10-09

1、查找表中多余的重復記錄,重復記錄是根據單個字段(peopleId)來判斷

select * from people   

where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1) 

 

2、刪除表中多余的重復記錄,重復記錄是根據單個字段(peopleId)來判斷,只留有rowid最小的記錄  

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、查找表中多余的重復記錄(多個字段)

select * from vitae a   

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

 

4、刪除表中多余的重復記錄(多個字段),只留有rowid最小的記錄

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、查找表中多余的重復記錄(多個字段),不包含rowid最小的記錄

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)   

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