Hello Derek,
One of the issues that I have with any kind of database is this - GIGO. It can only be as good as its creator and, because you are suggesting multiple creators, this makes for an impossibly large set of agreement and consistency. Such a database would have problems in being created or even being useable by police or forensic analysts/scientists because the knots tied and used would first have to be identified by name or a consistent description. If the analysts know nothing of the naming or description, how do they access any database? Even if they know the name of some or many knots, how do they know which one is present, if it has been collapsed or faired or even made in some different way? If they have a series of photos to look at, what do they know of chirality, wet/dry conditions, over-stress and under-stress, faired or tied differently, etc., etc.?
As to knot usage, why would such a database be useful? It would be akin to giving the analyst the ABOK and saying "it's in there somewhere" wouldn't it? Do you see the number of uses that simple knots can have? What of those uses that are not included? I do not wish to decry your noble efforts, but this is simply not something that can be achieved either easily or quickly - no low-hanging fruit there! What is needed instead is a method of HOW to analyze knots, not which knots are present.
Anyone calling themselves a knotting specialist/analyst/expert should be able to identify the knot. It is the method of analyzing the knot that matters, so that all knots are analyzed in a consistent manner - such things as the handedness, the tension applied, any twist applied and the implications for each. Those would be a starting point for beginning a description of methods, such that each knot could be analyzed in a consistent manner.
What is also needed is an agreed definition of the twists and turns that lines and knots make and the other external features and forces that make the knot work. Such a definition exists for mathematical knots (which are, by necessity all made as loops) but those are relatively simple knots used to describe particle, plane or solids actions and interactions. We have no such accepted definition in knot-tying - yes, many people use a similar language or term, but there is no universal or even consistent definition, let alone one accepted by all. Then again, all courts have different standards and methods of accepting evidence and expert testimony, so maybe it doesn't matter?!
With a definition, one could begin to assemble a database of those terms as they apply to various named knots in some consistent publication, probably ABOK, but where do you go from there? I think your idea is noble, as i said before, but I would ask whether or not you would feel that such a task could be achieved in several lifetimes? Ashley took eleven years to compile his book, which is necessarily incomplete, and he did not work alone (yes, he wrote it himself, but he culled the information from many others).
I feel that trying to arrive at a suitable and accepted definition of knot forms which, with suitable diagrams and supporting corroboration, could be used as the basis for a beginning definition of knots would be a good first task. Good luck with your search!
Lindsey