Just to clarify: do you want to insert all possible intersections into AB?

That is, for 2 A's and 3 B's, do you want to insert 6 rows into AB?

-Philip

> > I understand the concept - but I am not sure of the best way to
> > implement
> > it - for example if I insert 2 records into Table A and at the
> same
> > time 3
> > records into Table B - is there any way of auto-inserting the
> > neccessary
> > records in the Table AB - or do I have to also insert those at the
> > same time
> > from the client end ?