SQL刪除重復記錄的四種方式
作者:佚名
SQL數據庫中有重復的記錄?不要著急,使用下面幾種方法,您可以輕松查找到表中多余的重復記錄,并刪除掉。
在SQL數據庫中,經常會遇到重復記錄的情況,那么就需要SQL刪除重復記錄,下面為您列舉了四種SQL刪除重復記錄的方式,用于不同的情況,希望對您有所啟迪。
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、SQL刪除重復記錄,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)
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責任編輯:段燃
來源:
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