1.如下表结构;表ActivitySteps:
字段: from int,to int表数据:
from to
a b
b c
c d2.
如何通过一个sql查询,获得如下查询结果:
a
b
c
d3.
因此得到的结果是有顺序的,请问这个如何操作啊?
盼赐教!!
字段: from int,to int表数据:
from to
a b
b c
c d2.
如何通过一个sql查询,获得如下查询结果:
a
b
c
d3.
因此得到的结果是有顺序的,请问这个如何操作啊?
盼赐教!!
调试欢乐多
(
select from as column1 table
union all
select to column1 as table
)
order by column1
--FROM 和 TO 是oracle的关键字,不能用来做列名,非做不可的话加双引号。
[TEST@orcl] SQL>WITH t1 AS(
2 SELECT 'a' "FROM",'b' "TO" FROM DUAL UNION
3 SELECT 'b' "FROM",'c' "TO" FROM DUAL UNION
4 SELECT 'c' "FROM",'d' "TO" FROM DUAL
5 )SELECT COL
6 FROM( SELECT "FROM" COL FROM T1
7 UNION
8 SELECT "TO" FROM T1)
9 ORDER BY COL;C
-
a
b
c
d