Many thanks for that jenkolaka,
I'll save this post for a little later. I'm not sure people understand just how technically incapable I am. I haven't got to grips with foreign keys and the like yet, but have ordered a couple of books to hopefully get me going!
(I honestly didn't expect to have to know this stuff).
I'll have another bash at it when I learn a bit more from the books, and feel able to ask questions here in the hope of understanding the answers.
Your post looks like it will be perfect for when that time (hopefully) comes. I have copied and pasted it into a text file, and put it in my Security Assist folder for later. I appreciate the time and attention you put into it.
Helpful threads are all I'm after. I'm sorry you see a search for clarity as butting in and derailment. I can't help that; perhaps when you're less tired, you will be able to appreciate that. As I've said before, I do appreciate the help you've given and your input to the threads. Incidentally, in the thread I assume you are referring to, my input resulted in confirmation that a certain file - referred to in a tutorial - did not in fact exist, and successfully elicited advice on an alternative solution, whereas your input comprised insisting that the non-existent file did in fact exist. So I'm confused as to your definition of derailment. Perhaps you should review it. You should perhaps also say 'I' rather than 'we' regarding standards.