在Oracle中找出重复的纪录的方法

SQL> desc test
 Name                                      Null?    Type
 ----------------------------------------- -------- -----------------
 ID                                                 NUMBER
--表 test有重复的记录1,10
SQL> select * from test;

        ID
----------
         1
         2
         3
         4
        10
         1
         1
         1
         1
         1
        10

11 rows selected.
--查询表中的哪些记录有重复

SQL> select * from test group by id having count(*)>1;

        ID
----------
         1
        10
--查询出没有重复记录的结果集
SQL> select * from test group by id;

        ID
----------
         1
         2
         3
         4
        10

SQL> select distinct * from test;

        ID
----------
         1
         2
         3
         4
        10
--删除重复的记录
SQL> delete from test a where a.rowid!=(select max(rowid) from test b
  2  where a.id=b.id);

6 rows deleted.

SQL> commit;

Commit complete.
--删除后的查询结果集
SQL> select * from test;

        ID
----------
         2
         3
         4
         1
        10

原文转自：http://www.ltesting.net