I would do this (after I've finished transferring several hundred web sites, slept for a week, then caught up with work) by:
- adding some extra columns to the mines table for sub-type products, thus we might have:
type1 | type 2 | type 3
lead | silver | something else
(ordinarily I'd do this with a link table of mine < > mineral, but they're more relevant where you've got one to many, whereas here we've got one to a few)
The mine would be classified as the primary product, and this would be used to build the reference:
Cwmorthin-Slate-Quarry for example
But if 'cwmortin' (in this example) also produced gold then it would state that on results pages, state that on the mine information page, and it would be findable through searches for any product extracted. Just as mines can be found on their name and alternate name.
I wouldn't add a classification called 'Lead/Silver' because that's not a single product, so people wouldn't know to search for 'Lead', 'Silver' or 'Lead/Silver'. 'Lead/Silver' would then beg 'Lead/Zinc' and who knows where we'd end :lol:
Adding 'other' and a free text entry would be a disaster! We'd potentially have multiples of the same 'other', variant spellings of them etc.
:flowers: :flowers:
my orders are to sit here and watch the world go by