合并两张表

[durking]

请问大虾，我现在有两张表
表A 结构为 COLUMN1,COLUMN2,COLUMN3
表B 结构为 COLUMN1,COLUMN2

SELECT * FROM 表A
COLUMN1,COLUMN2,COLUMN3
A1 A2 A3

SELECT * FROM 表B
COLUMN1,COLUMN2
B1 B2


现在我能不能写一条sql 同时查询表A，表B
结果为
COLUMN1,COLUMN2,COLUMN3
A1 A2 A3
B1 B2 null

[ws_hgo]

使用union all
连接表的时候
表字段的数量必须一样多
select * from a
union all
select *,null from b

[linguojin11]

使用union all
连接表的时候
表字段的数量必须一样多
select * from a
union all
select *,null from b

[nalnait]

UNION
UNION ALL

[csdyyr]

SELECT COLUMN1,COLUMN2,COLUMN3 FROM A
UNION ALL
SELECT COLUMN1,COLUMN2,NULL FROM B

[dawugui]

select * from a
union all
select * , column3 = '' from b

[Rewiah]

select * from 表A 
union all
select *,null from 表B

[dawugui]

select * from a
union all
select * , null from b

[Usher2006]

select * from A
union all
select * , null from B