hi i have a table like this.

A B

1 2
3 7
6 4
2 1
7 3
8 5

I need the find the row which are like

A B
1 2
2 1
3 7
7 3

ie rows like a=b and b=a

and in that i need any one pair not replica

A B

1 2
3 7

or else

A B

2 1
7 3

regards,
deepa