欢迎投稿

今日深度:

SQL合并结果集(Union)

SQL合并结果集(Union)


假设有表(UserTB):



1、Union(不允许重复)

SELECT  *
FROM    dbo.UserTB
WHERE   deptId IN ( 1, 3 )
UNION
SELECT  *
FROM    dbo.UserTB
WHERE   deptId IN ( 1, 2 )
结果:


2、Union All(允许重复)

SELECT  *
FROM    dbo.UserTB
WHERE   deptId IN ( 1, 3 )
UNION ALL
SELECT  *
FROM    dbo.UserTB
WHERE   deptId IN ( 1, 2 )
结果:



www.htsjk.Com true http://www.htsjk.com/shujukunews/879.html NewsArticle SQL合并结果集(Union) 假设有表(UserTB): 1、Union(不允许重复) SELECT *FROM dbo.UserTBWHERE deptId IN ( 1, 3 )UNIONSELECT *FROM dbo.UserTBWHERE deptId IN ( 1, 2 ) 结果: 2、Union All(允许重复) SELECT *FROM dbo....
评论暂时关闭