Query Preparation

[Sameer Kumar]

Hi All,

ID A B
1 200 500
2 100 300
3 555 666
4 666 555
5 541 256
6 454 45454
7 5656 122

I have a table with the sample data mentioned above.
I need to find the records where there is a circular reference between coloumns A and B.
For ex: record 3 & 4 refers to each other.
3 555 666
4 666 555

Can any one help me out how we can prepare this query.

Regards,
Sameer

[Christophe Verré]

select A,B from tbl t1 where exists (select 'X' from tbl t2 where t2.a = t1.b and t2.b = t1.a) ? Not sure.