Re: PRIMARY KEYS

>>>>> "MvO" == Martijn van Oosterhout <kleptog@svana.org> writes:

MvO> Number or Drivers Licence number as primary key is forbidden. If
MvO> you're permitted to have the information you're allowed to store
MvO> it but you sure as hell can't index your filing cabinets on it or
MvO> make it a primary key.

What exactly is the difference between

UNIQUE INDEX on a NOT NULL column of driver license numbers with no
other primary key on that table

and

PRIMARY KEY on that same column?

The only thing that changed was the name.

But then, try explaining that to your lawmakers...

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Vivek Khera, Ph.D.                Khera Communications, Inc.
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