1、临时表：
1.1）实例1
if(OBJECT_ID('tempdb..#a') IS NOT NULL) drop table #a;
if(OBJECT_ID('tempdb..#b') IS NOT NULL) drop table #b;
SELECT name into #a from syscolumns a with(nolock) where id=OBJECT_ID('NewsLetterSystem_Subscriber');
SELECT name into #b from syscolumns b where id=OBJECT_ID('tmpContact_130828005535769_5243_f0b7');
select * from #a,#b
where #a.name=#b.name;
1.2） 实例2
if(OBJECT_ID('tempdb..#a') IS NOT NULL) drop table #a;
select * into #a from Categories;
select * from #a;
2、公用表：
2.1）实例1
with
cr as
(
select CountryRegionCode from person.CountryRegion where Name like 'C%'
) select * from person.StateProvince where CountryRegionCode in (select * from cr) --其中cr是一个公用表表达式，该表达式在使用上与表变量类似
2.2） CTE后面必须直接跟使用CTE的SQL语句（如select、insert、update等），否则，CTE将失效。如下面的SQL语句将无法正常使用CTE：
with
cr as
(
select CountryRegionCode from person.CountryRegion where Name like 'C%'
)
select * from person.CountryRegion -- 应将这条SQL语句去掉
-- 使用CTE的SQL语句应紧跟在相关的CTE后面 --
select * from person.StateProvince where CountryRegionCode in (select * from cr)
2.3）CTE后面也可以跟其他的CTE，但只能使用一个with，多个CTE中间用逗号（,）分隔，如下面的SQL语句所示：
with
cte1 as
(
select * from table1 where name like 'abc%'
),
cte2 as
(
select * from table2 where id > 20
),
cte3 as
(
select * from table3 where price < 100
)
select a.* from cte1 a, cte2 b, cte3 c where a.id = b.id and a.id = c.id
2.4）实例4
with ta as (
SELECT name from syscolumns a with(nolock) where id=OBJECT_ID('NewsLetterSystem_Subscriber')
),
tb as
(
SELECT name from syscolumns b where id=OBJECT_ID('tmpContact_130828005535769_5243_f0b7')
)
select * from ta,tb where ta.name=tb.name
ps:将一个库中数据插到另一个库中：
语句：
insert into b.dbo.b
select * from a.dbo.a
实例1：
insert into dbname1.dbo.tabname1
select * from dbname2.dbo.tabname2
判断临时表是否存在sql:
if(OBJECT_ID('tempdb..#c') is not null) drop table #c
if(OBJECT_ID('tempdb..#e') is not null) drop table #e
if(OBJECT_ID('tempdb..#newc') is not null) drop table #newc