查询SQL Server中三个表的数据

Question

我有叫3个表tbl_monday,tbl_tuesday并tbl_wednesday认为由数据如下:

tbl_monday

id    empid   Plan
---------------------
1     6       Mon_27
2     6       Mon_27
3     6       Mon_27

tbl_tuesday

id    empid   Plan
--------------------
1     6       Tue_28
2     6       Tue_28
3     6       Tue_28     

tbl_wenesday

id  empid     Plan
------------------
1     6       Wed_29
2     6       Wed_29
3     6       Wed_29

有没有简单的方法来获得这样的结果？

empid    Plan
----------------------
6       Mon_27
6       Tue_28
6       Wed_29

Answer 1

您可以union在三个表之间进行查询,这将提供所有查询的唯一结果:

SELECT empid, [plan] FROM tbl_monday
UNION
SELECT empid, [plan] FROM tbl_tuesday
UNION
SELECT empid, [plan] FROM tbl_wednesday

SQLFiddle