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SQL重复记录查询

时间:2021-07-01 10:21:17 帮助过:7人阅读

1.Select COUNT(distinct ann_id) from dmdb.t_bond_ann_att_info where last_update_time >= 2018-03-09 14:00:00; 2.Select COUNT(id) from dmdb.t_bond_ann_info where create_time >= 2018-03-09 14:00:00; 3.Select a.* from dmdb.t_bond_ann_info a where a.id not in ( select ann_id from t_bond_ann_att_info where last_update_time >= 2018-03-09 14:00:00 ) and a.create_time >= 2018-03-09 14:00:00; 4.Select distinct a.ann_id from dmdb.t_bond_ann_att_info a where a.ann_id not in ( select id from t_bond_ann_info where create_time >= 2018-03-09 11:10:00 ) and last_update_time >= 2018-03-09 11:10:00; 5.select * from t_bond_ann_att_info where ann_id in (13441,13442) 6.delete from t_bond_ann_att_info where ann_id in (13441,13442) 7.Select * from dmdb.t_bond_ann_info order by create_time DESC limit 800 8.select * from dmdb.t_bond_ann_att_info where ann_id=15068 --------------------------------------------------------------------------- 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) 例二: select * from testtable where numeber in (select number from people group by number having count(number) > 1 ) 可以查出testtable表中number相同的记录 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 * fromvitae 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 fromvitae 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 * fromvitae 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) (二) 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 方法二 有两个意义上的重复记录,一是完全重复的记录,也即所有字段均重复的记录,二是部分关键字段重复的记录, 比如Name字段重复,而其他字段不一定重复或都重复可以忽略。 1、对于第一种重复,比较容易解决,使用 select distinct * from tableName 就可以得到无重复记录的结果集。 如果该表需要删除重复的记录(重复记录保留1条),可以按以下方法删除 select distinct * into #Tmp fromtableName drop tabletableName select * into tableName from#Tmp drop table #Tmp 发生这种重复的原因是表设计不周产生的,增加唯一索引列即可解决。 2、这类重复问题通常要求保留重复记录中的第一条记录,操作方法如下 假设有重复的字段为Name,Address,要求得到这两个字段唯一的结果集 select identity(int,1,1) as autoID, * into #Tmp fromtableName select min(autoID) as autoID into #Tmp2 from #Tmp group byName,autoID select * from #Tmp where autoID in(select autoID from #tmp2) 最后一个select即得到了Name,Address不重复的结果集(但多了一个autoID字段,实际写时可以写在select子句中省去此列) (四) 查询重复 select * from tablename where id in( select id fromtablename group by id having count(id) > 1 )

 

SQL重复记录查询

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