SQL话语中的两个常用的关键字:INTERSECT(交集)和UNION(并集)

SQL语句中的两个常用的关键字:INTERSECT(交集)和UNION(并集)

查询几张表中并集
select b.* from CorpBasic b where  1=1
and b.ID in(
select CorpID from CorpSMS  where 1=1  and RoleID in(-999 ,1)
union
select CorpID from CorpWap where 1=1  and RoleID in(-999 ,1)
union
select CorpID from CorpComWeb where 1=1  and RoleID in(-999 ,1)
      )

查询几张表中交集
select b.* from CorpBasic b where  1=1
and b.ID in(
select CorpID from CorpSMS  where 1=1  and RoleID in(-999 ,1)
intersect
select CorpID from CorpWap where 1=1  and RoleID in(-999 ,1)
intersect
select CorpID from CorpComWeb where 1=1  and RoleID in(-999 ,1)
      )