Tim, > Ello all... > > I want to implement a "matrix" style table(s) but not sure > how to go about it. Basically I have a table of "things" > that are compatiable with zero or more other "things", e.g.: > > 1 2 3 4 5 > 1 X X > 2 X X > 3 X X X > 4 X X X > 5 X X > > Now I could have a "matrix" table that contains two keys, but > to make sure everything works properly I'd have to have two > entries for each pair...
That's the way you'd have to do it... > Does anyone know of a way to get around this? The query is actually very quick to return stuff. SELECT * (or whatever) FROM Tbl WHERE x <> y Because, this would return ALL records where x and y aren't the same (because if they were, it wouldn't be a matrix). It's actually really easy to create this type of table and use it (as I have) and the queries are not a big issue, so long as you use the correct queries to get everything. The only other way around it, is to create a second table that contains the "links" between things. That way, you have one table of ID's, and a table of "links" and do a sub-select SELECT * FROM tblid WHERE tblid.idfld IN (SELECT tbllinks.linkids FROM tbllinks WHERE tbllinks.idfld = tblid.idfld) Or something like that... You could then do a JOIN (or something) that returns all the ID's and null if they aren't in the list... Just some thoughts Paul -- ** Archive: http://www.mail-archive.com/dev%40lists.cfdeveloper.co.uk/ To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] For human help, e-mail: [EMAIL PROTECTED]
