ORACLE 删除重复数据

比如现在有一人员表 (表名:peosons)

  (1)若想将姓名、身份证号、住址这三个字段完全相同的记录查询出来

  select p1.*

  from persons p1,persons p2

  where p1.id<>p2.id

  and p1.cardid = p2.cardid and p1.pname = p2.pname and p1.address = p2.address

  可以实现上述效果。

(2)删除相同行(除主键外,其它属性值相同的行)

delete from dept a where a.deptno<>
(
select min(deptno) from dept t group by(dname,loc)
having count(*)>1 and a.dname=t.dname and a.loc=t.loc
);

其中,dept的主键是deptno,针对(dname,loc)这两个属性值相同的行,把重复的删除,留下deptno值最小的那一行

(3)你建的表没有主键?也许你的表没。

create table mytemp as
select user_id,company_id,fee_date,insure_id /*列出所有的列*/ from t_insure_feed group by(user_id,company_id,fee_date,insure_id /*列出所有的列*/);

查询:select * from mytemp;

======================
1.查询重复(usr_id)的行:
select user_id from t_insure_feed group by user_id having count(*)>1;
2.全部删除重复的行!(一个都不剩下)
delete from t_insure_feed where user_id in (select user_id from t_insure_feed group by user_id having count(*)>1);
提示:用rollback可以恢复。

其他方法:没有尝试,希望各位尝试一下了

几个删除重复记录的SQL语句

  1.用rowid方法

  2.用group by方法

  3.用distinct方法

  1。用rowid方法

  据据oracle带的rowid属性,进行判断,是否存在重复,语句如下:

  查数据:

  select * from table1 a where rowid !=(select max(rowid)

  from table1 b where a.name1=b.name1 and a.name2=b.name2……)

  删数据:

  delete from table1 a where rowid !=(select max(rowid)

  from table1 b where a.name1=b.name1 and a.name2=b.name2……)

  2.group by方法

  查数据:

  select count(num), max(name) from student --列出重复的记录数,并列出他的name属性

  group by num

  having count(num) >1 --按num分组后找出表中num列重复,即出现次数大于一次

  删数据:

  delete from student

  group by num

  having count(num) >1

  这样的话就把所有重复的都删除了。

  3.用distinct方法 -对于小的表比较有用

  create table table_new as select distinct * from table1 minux

  truncate table table1;

  insert into table1 select * from table_new;

  查询及删除重复记录的方法大全

  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)

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