sqlserver集合操作

SQLServer2005通过intersect,union,except和三个关键字对应交、并、差三种集合运算

详细如下

use tempdb
go
if (object_id ('t1' ) is not null ) drop table t1
if
(object_id ('t2' ) is not null ) drop table t2
go
create table t1 (a int
)
insert into t1 select 1 union select 2 union select 3
create table t2
(a int )
insert into t2 select 3 union select 4 union select 5
go

--求表并集
select * from t1 union select * from t2
go

--求表并集不过滤重复
select * from t1 union all select * from t2
go

/*
1
2
3
3
4
5*/

--求t1对t2的差集
select * from t1
except select * from t2
go
/*
1
2*/

--求t1对t2的交集
select * from
t1 intersect select * from t2
go
/*