Coming up with a schema that works with multiple manufacturers is the big challenge.
On Thu, Oct 1, 2015 at 6:01 PM, Jay Jaeger <cu...@charter.net> wrote: > On 9/25/2015 4:03 PM, m...@markesystems.com wrote: > >>> 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. > > JRJ > -- Bill vintagecomputer.net
