解讀五種查詢數據庫中重復記錄的方法

2024-08-31 00:46:53

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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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