On Jan 23, 1:41 am, "Tony Toews [MVP]" wrote:
I always use an autonumber PK and a uniqui index set on the two FK fields.

Why? No particular good reason. One of my database rules is that all tables have
an autonumber primary key.

The theorists will argue. I don't care.

Would you care for a pragmatist to offer a counter argument?

I never seek to add columns where an attribute does not exist in the
reality being modelled; sometimes I do end up adding something
'artificial' but only when there is a "good data modelling" reason for
doing so.

In the scenario described, there is a two-column "all key" table which
means it is in 5NF. From a "data modelling" point of view I can't see
a case for adding an 'artifical key'.

Jamie.

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