eliminate same kind of pairs

[amie8202]

Hi,
I have a table A like something like this:
| a b c d
--|----------------
1|(1, 2), (0, 0)
2|(3, 1), (1, 2)
3|(0, 0), (3, 1)
4|(0, 0), (1, 2)

In this, I want to eliminate the duplicate where there is same kind of pair (1,2) (0,0) and (0,0) (1,2).
So I would just end up with 3 rows of table
with eliminate either of that pairs...

How do I do this with sql command???

Thanks in advance!!

 

[dmcmunn]

delete a
from TableA a

inner join TableA b
on ( (a.col1 = b.col3)
and (a.col2 = b.col4)
and (b.col1 = a.col3)
and (b.col2 = a.col4))

where not
( (a.col1 = b.col1)
and (a.col2 = b.col2)
and (a.col3 = b.col3)
and (a.col4 = b.col4))

-- this will delete the value with the largest numbers in the first two columns,
-- to remove the smaller switch signs
-- this won't work if all the numbers are duplicated
and ((a.col1 > b.col1)
or (a.col2 > b.col2))