我有两个专栏的节日和活动，比如
节日
id | name | modified_date
-----------------------------------
12 | fest 1 | 2012-03-14 17:45:40
13 | fest 2 | 2012-03-14 17:45:40
15 | fest 4 | 2012-03-14 17:45:40
11 | fest 5 | 2012-03-14 17:45:40
事件
id | name | modified_date
-----------------------------------
14 | envt 1 | 2012-03-14 17:45:40
15 | envt 2 | 2012-03-14 17:45:40
16 | envt 4 | 2012-03-14 17:45:40
17 | envt 5 | 2012-03-14 17:45:40
我的应用程序中有一个页面显示最近的更新，点击每个列表，它将重定向到相应的活动或节日。
为此，我有以下查询
select id,name,modified_date from events
UNION
select id,name,modified_date from festival
order by modified_date desc
这将返回类似的表格
id | name | modified_date
-------------------------------------
12 | fest 1 | 2012-03-14 17:45:40
13 | fest 2 | 2012-03-14 17:45:40
--------------------------------------------
但我的问题是，我还需要一个专栏来理解这一行代表一个事件或节日。。类似的东西
id | name | modified_date | type
---------------------------------------------------
12 | fest 1 | 2012-03-14 17:45:40 | festival
15 | evnt 2 | 2012-03-14 17:45:40 | event
请帮忙提前感谢
select id, name, modified_date, 'event' as type
from events
UNION
select id, name, modified_date, 'festival' as type
from festival
order by modified_date desc
这应该可以完成
select id,name,modified_date, 'event' AS type from events
UNION
select id,name,modified_date, 'festival' AS type from festival order by modified_date desc