On 9/25/2015 4:03 PM, mark at markesystems.com
> Not sure
why you have VARCHARs for primary keys, why not use the
> conventional auto-increment int so you can dispense with
> the LastGeneratedArtifactID table.
Because my artifact ID's are not always just
numbers. In some cases
they may already be marked on an artifact (though typically not for
manuals - but this is just the first of a set of such projects, and they
*are* marked on many of my computer boards).
For anyone who might care, today I decided to move to an auto-increment
key on the Manual table, and then use that key in the Manual_Artifact,
Manual_File and Manual_Machines tables. (But not the ArtifactID ;) ).
It was an outgrowth of doing some data clean up and realizing that a
manual from one manufacturer was sometimes related to a machine by a
different manufacturer (e.g., ABLE computer boards in Digital Equipment
machines). I was going to sometimes end up with two manufacturers in
the Manual_Machines table, which was apt to get confusing over time.
So I will now have a Manual_MFG column, which is used only in the Manual
table, and a Machine_MFG column, used only in the Manual_Machine table.
A new Manual_Key will be used in place of the Machine_MFG:Manual_Number
pair I had been using all over the place.
I still have to finish the model, and will update the PDF I put on my
website at some point in the next day or so.