如何用一个视图合并两张表

[coldestrain]

表1
ColumnA ColumnB
1 aaa
2 bbb
3 ccc
表2
ColumnC ColumnD
4 ddd
5 eee
6 fff
现在需要一个视图返回结果为
ColumnAC ColumnB ColumnD
1 aaa null
2 bbb null
3 ccc null
4 null ddd
5 null eee
6 null fff

[nononono]

select语句应为:

select ColumnA as ColumnAC, ColumnB, null as ColumnD from 表1
union
select ColumnC as ColumnAC, null as ColumnB, ColumnD from 表2
order by ColumnAC

[coldestrain]

ok