I have never fully understood the usage/Purpose of the autonumber fields that are set into any new table created. So perhaps someone can explain the usage/purpose/need for this type of field.
Below are some related tables from an application I have. The Primary Key fields, in the tables that have them are not auto numbers, but are generated from one of two tables that provide a company specific set of unique ID numbers.
You will note that the tables lnkChangeTrain and lnkChangeApprove have no primary key fields. Both of these tables are nothing more than groups of employees (either for training and/or approving) that have been assigned to specific change requests.
I see no need for an autonumber field in those tables that already have a unique, primary key field. That leaves the tables lnkChangeTrain and lnkChangeApprove and I would like to know how the database, the users, or myself benefits in anyway from having an autonumber primary keyed field in those two tables.