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On Tue, Apr 15, 2008 at 6:55 PM, Colin Wetherbee <[EMAIL PROTECTED]> wrote: > Scott Webster Wood wrote: > > > > > You shouldn't really need to go recursing through a data tree to > > > come up with all the parts of a single fact. > > > > > > > Well that is unless you are wanting to inherit data from linked > > elements further up a link list without re-posting redundant > > information. > > > > That's true enough in your situation, but then you trade speed against data > size. I suspect traversing a data hierarchy inside a database, with SQL > alone, won't be too pleasant when it comes to performance. > > > > > > > Then, instead of storing property description text separately in > > > your categories and categoryLinks tables, have a foreign key > > > reference the id column in the property table. > > > > > > > > > > In addition, I'd get rid of your categoryLinks table altogether. > > > > > > > Think like an object oriented programmer for a second. The > > individual entries in the main Categories table and the individual > > items tables are 'definitions' of that particular 'object' with some > > 'default' values filled in. The additional (seemingly redundant) > > entries on the link table allow the link to 'override' the default > > value(s) with local, instance specific ones. My goal was as a > > time/work saving measure (from the administration perspective) to > > allow 'children' elements to have blank entries where the values > > would get inherited down from parents. > > > > That makes sense. I haven't delved into the object-relational properties of > databases, but I wonder if that kind of inheritance is easier to achieve > than it seems? > > > > Besides, my keywords are working nicely, I was just curious about SQL > > and if there was any conditional recursive looping in the various > > scripting syntax. (what is the plural of syntax? synti?) > > > > If the object-relational thing works out, you may not have to worry about > recursion. I'd suggest investigating that route. > > If all else fails and you still want to keep these operations inside the > database, stored procedures are great for that sort of thing. I write > utility and analysis functions in PostgreSQL's PL/Perl all the time, and I > expect it would be much easier to traverse a hierarchy if you were able to > do so in a language like that instead of in SQL. > > As for the plural of "syntax", I don't think there is one, but it's likely > possible to pluralize etymologically ancestral versions of it. :) > > Colin > -- Matthew O. Persico
