Forum Discussion
Key Field Question
Actually, this is two tables, in my opinion, not one with this concatenated code field.
The main table (the one-side of the relationship) is the "Master Card."
Each card type is listed here in this table.
Each variation is listed in a related table (the many-side of the relationship).
If a card has one and only one instance, then there are no records for it in the variation table. As you add variations, they are recorded in the variation table with a foreign key reflecting the Card's Primary Key and a sequence letter for it, e.g. "1a". That way, you can join the two tables to get a complete list.
That does leave the problem of a single card being "1" and having no "a" or "b" etc.
You could approach that in two ways. One, accept the fact that the master card is "1", "2", etc. and you'll only see the variation code IF there are actually variations. Two, finesse the original master with the "A" as suggested. I prefer the first option.
