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A  B
1  a
2  b
3  c
4  d
 
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ÔõôûÓÐcd

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SELECT DISTINCT T1.B+T2.B
from TB T1
INNER JOIN TB T2 WHERE T1.B <T2.B

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SQL code:
--> Title : Generating test data [tb]
--> Author :
--> Date : 2009-12-03 11:11:25
if object_id('[tb]') is not null drop table [tb]
go
create table [tb] (A int,B nvarchar(2))
insert into [tb]
select 1,'a' union all
select 2,'b' union all
select 3,'c' union all
select 4,'d'

select a.b+b.b from [tb] a, [tb] b
where a.a<B.a
/*

----
ab
ac
bc
ad
bd
cd

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*/

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SQL code:

--> ²âÊÔÊý¾Ý£º[TB]
if object_id('[TB]') is not null drop table [TB]
create table [TB]([A] int,[B] varchar(1))
insert [TB]
select 1,'a' union all
select 2,'b' union all
select 3,'c' union all
select 4,'d'

select A.B+B.B from [TB] A,TB B where A.B<>B.B
order by 1

/*

----
ab
ac
ad
ba
bc
bd
ca
cb
cd
da
db
dc

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*/

drop table TB



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