1、臨時表：

1.1）實例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） 實例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）實例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是一個公用表表達式，該表達式在使用上與表變量類似

2.2） CTE後面必須直接跟使用CTE的SQL語句（如select、insert、update等），否則，CTE將失效。如下面的SQL語句將無法正常使用CTE：

with
cr as
(
   select CountryRegionCode from person.CountryRegion where Name like ‘C%‘
)
select *
 
 from person.CountryRegion -- 應將這條SQL語句去掉
-- 使用CTE的SQL語句應緊跟在相關的CTE後面 --
select * from person.StateProvince where CountryRegionCode in (select * from cr)

2.3）CTE後面也可以跟其他的CTE，但只能使用一個with，多個CTE中間用逗號（,）分隔，如下面的SQL語句所示：

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）實例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

MSSQL 臨時表和公用表使用案例