假設有表(UserTB):

1、Union(不允許重復)
?
1 2 3 4 5 6 7 SELECT * FROM dbo.UserTB WHERE deptId IN ( 1, 3 ) UNION SELECT * FROM dbo.UserTB WHERE deptId IN ( 1, 2 )結果:

2、Union All(允許重復)
?
1 2 3 4 5 6 7 SELECT * FROM dbo.UserTB WHERE deptId IN ( 1, 3 ) UNION ALL SELECT * FROM dbo.UserTB WHERE deptId IN ( 1, 2 )結果:
