删除重复记录
2014-12-15 13:40
99 查看
在几千条记录里,存在着些相同的记录,如何能用SQL语句,删除掉重复的呢?谢谢! 1、查找表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断 select * from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1) 2、删除表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断,只留有rowid最小的记录 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、查找表中多余的重复记录(多个字段) select * from vitae a where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1) 4、删除表中多余的重复记录(多个字段),只留有rowid最小的记录 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、查找表中多余的重复记录(多个字段),不包含rowid最小的记录 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) 比方说在A表中存在一个字段“name”,而且不同记录之间的“name”值有可能会相同, 现在就是需要查询出在该表中的各记录之间,“name”值存在重复的项; Select Name,Count(*) From A Group By Name Having Count(*) > 1 如果还查性别也相同大则如下: Select Name,sex,Count(*) From A Group By Name,sex Having Count(*) > 1
相关文章推荐
- 删除重复的记录,并保存第一条记录.
- 在Oracle中如何利用Rowid查找和删除表中的重复记录(转)
- [收藏]在SQL中删除重复记录(多种方法)
- 在SQL中删除重复记录(多种方法) [转]
- 几个删除重复记录的SQL语句
- 删除重复记录的问题
- 删除数据库中重复记录
- 查找、删除表中重复的记录
- 在SQL中删除重复记录的多种方法
- 在Oracle中如何删除重复的记录?
- 在SQL Server中快速删除重复记录
- 在SQL中删除重复记录(多种方法)
- 在SQL Server中快速删除重复记录(多图)
- 在SQL中删除重复记录(多种方法)
- [转载]在SQL中删除重复记录(多种方法)
- 在Oracle中如何利用Rowid查找和删除表中的重复记录
- 如何删除表中的重复记录?
- 在SQL中删除重复记录(多种方法)[转]
- SQL删除逻辑重复记录的最简方法
- 有关重复记录的删除