怎么关联同一个表里的字段

Question

SELECT t1.id,
       (SELECT t2.name FROM t_table t2 WHERE t2.id = t1.superid) supername,
       t1.name
  FROM t_table t1

Answer 1

select t1.id,t2.name,t1.name from table t1,table t2 where t1.superid=t2.id(+)

Answer 2

有图有真相：

我刚发现，表里有2条一样的数据，如下：id  superid  name
1     4       aaa
2     5       bbb
1     4       aaa
2     5       bbb
3             ccc
4             ddd
5             eee结果查询结果出来2对数据，如下：
id    supername        name
1        ddd           aaa
2        eee           bbb
1        ddd           aaa
2        eee           bbb
1        ddd           aaa
2        eee           bbb
1        ddd           aaa
2        eee           bbb
3                      ccc
4                      ddd
5                      eee为啥会多了4行，怎么出现如下的结果集：
id    supername        name
1        ddd           aaa
2        eee           bbb
1        ddd           aaa
2        eee           bbb
3                      ccc
4                      ddd
5                      eee

Answer 3

我刚发现，表里有2条一样的数据，如下：id  superid  name
1     4       aaa
2     5       bbb
1     4       aaa
2     5       bbb
3             ccc
4             ddd
5             eee结果查询结果出来2对数据，如下：
id    supername        name
1        ddd           aaa
2        eee           bbb
1        ddd           aaa
2        eee           bbb
1        ddd           aaa
2        eee           bbb
1        ddd           aaa
2        eee           bbb
3                      ccc
4                      ddd
5                      eee为啥会多了4行，怎么出现如下的结果集：
id    supername        name
1        ddd           aaa
2        eee           bbb
1        ddd           aaa
2        eee           bbb
3                      ccc
4                      ddd
5                      eeeSELECT T1.ID, T2.NAME, T1.NAME
  FROM TEST T1, (SELECT DISTINCT ID FROM TEST) T2
 WHERE T1.SUPERID = T2.ID(+)

Answer 4

我刚发现，表里有2条一样的数据，如下：id  superid  name
1     4       aaa
2     5       bbb
1     4       aaa
2     5       bbb
3             ccc
4             ddd
5             eee结果查询结果出来2对数据，如下：
id    supername        name
1        ddd           aaa
2        eee           bbb
1        ddd           aaa
2        eee           bbb
1        ddd           aaa
2        eee           bbb
1        ddd           aaa
2        eee           bbb
3                      ccc
4                      ddd
5                      eee为啥会多了4行，怎么出现如下的结果集：
id    supername        name
1        ddd           aaa
2        eee           bbb
1        ddd           aaa
2        eee           bbb
3                      ccc
4                      ddd
5                      eee更正：
SELECT T1.ID, T2.NAME, T1.NAME
  FROM TEST T1, (SELECT DISTINCT ID,NAME FROM TEST) T2
 WHERE T1.SUPERID = T2.ID(+)