How to compare value pair of one table with value pair of another table

Here is the problem:
--------
create table A( a1 int, a2 int)
create table B( b1 int, b2 int)

insert A values(1,1)
insert A values(1,2)
insert A values(2,1)
insert A values(2,3)
insert A values(3,1)
insert A values(3,3)

insert B values(1,1)
insert B values(1,2)
insert B values(3,2)
insert B values(2,2)

What is the SQL query to find out the pairs existing in B, but not in A ?

I can solve this by using string functions, but my problem is I have to write a query that can execute on MSSQL, DB2 and ORACLE, and as you know they have differnt syntax for string functions.

Thanks in advance.

Regards,
s99shah.pairs in B but not in A? left outer join, check for unmatched rows --
select b1, b2
from B
left outer
join A
on b1 = a1
and b2 = a2
where a1 is null

rudy
http://r937.com/|||Hi,

TRY THIS

Select B.* from a,b
where (+) a1 = b1;