On Dec 11, 8:14 pm, Jerry Whittle
wrote:
The only purpose of an autonumber is to be
unique when used as the primary key in a table.

FWIW I don't think that is correct. The purpose of Autonumber is auto-
generate a value according to an algorithm (increment, random or --
extrapolating slightly -- GUID).

There is nothing inherent about Autonumber that guarantees uniqueness
(even for GUIDs!) If you want uniqueness then you have to maintain a
unique constraint on it.

There is no requirement to use the PRIMARY KEY designation for a table
at all, let alone use it on the Autonumber column where one exists.

Jamie.

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