数据库查重复记录
數據庫查重復記錄
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
代碼如下:
select * from people
where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)
注意:這里的重復是指所有列的數據相同
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
代碼如下:
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)
代碼如下:
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
代碼如下:
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
代碼如下:
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)
6、查詢表某列的重復數據
select name from people group by name having count(name) > 1
總結
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