新聞中心
這里有您想知道的互聯(lián)網(wǎng)營(yíng)銷(xiāo)解決方案
SQL刪除重復(fù)記錄的四種方式
在SQL數(shù)據(jù)庫(kù)中,經(jīng)常會(huì)遇到重復(fù)記錄的情況,那么就需要SQL刪除重復(fù)記錄,下面為您列舉了四種SQL刪除重復(fù)記錄的方式,用于不同的情況,希望對(duì)您有所啟迪。

1、查找表中多余的重復(fù)記錄,重復(fù)記錄是根據(jù)單個(gè)字段(peopleId)來(lái)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(fù)記錄,重復(fù)記錄是根據(jù)單個(gè)字段(peopleId)來(lái)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(fù)記錄(多個(gè)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(fù)記錄(多個(gè)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)
【編輯推薦】
對(duì)SQL表結(jié)構(gòu)的查詢(xún)
表添加字段的SQL語(yǔ)句寫(xiě)法
sql查詢(xún)中time字段的使用
SQL Xml字段的修改方法
SQL定義Xml字段
本文標(biāo)題:SQL刪除重復(fù)記錄的四種方式
網(wǎng)頁(yè)URL:http://www.dlmjj.cn/article/dpdccso.html


咨詢(xún)
建站咨詢(xún)
