MYSQL查詢重復記錄的方法
作者：佚名
重復記錄是我們使用MYSQL數據庫經常會遇到的問題，下文就為您介紹幾種查詢重復記錄的方法，供您參考學習之用。
MYSQL查詢重復記錄的方法很多，下面就為您介紹幾種最常用的MYSQL查詢重復記錄的方法，希望對您學習MYSQL查詢重復記錄方面能有所幫助。
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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責任編輯：段燃
來源：
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