Russ,
Really useful response, thanks.
I had thought about your third option but as I figured there'd be a
lot of empty fields I didn't give it much consideration. I might
actually go down that route until I have a better understanding of
generic relations.
Thanks again.
j.
On Jun 29, 2:20 am, "Russell Keith-Magee" <[EMAIL PROTECTED]>
wrote:
> On 6/28/07, Jamie Pittock <[EMAIL PROTECTED]> wrote:
>
>
>
> > I don't want to code myself into a corner, so when I start looking at
> > features such as allowing users to search all venues would I be best
> > with one parent model or will I be ok keeping them separate? The
> > different types of venues have quite a number of different attributes
> > btw which is why they are different models rather than simply
> > categoried.
>
> Model inheritance sounds good on paper, but in practice, it gets
> somewhat inconvenient - lots of table joins to get at basic
> attributes, etc. If you have very few common attributes anyway,
> generic relations are probably worth investigation.
>
> However, as always, YMMV. My only reservation in recommending generic
> relations is that they aren't fully integrated with admin yet (though
> there is a patch floating around to integrate them with
> newforms-admin), and they're not fully documented. However, if you're
> willing to put up with those limitations, it sounds like they could be
> a good match for your needs.
>
> A third approach that you haven't mentioned is to have a single
> 'object' table that is sparse; i.e., instead of
>
> class Bar(Model):
> name = CharField()
> number_of_bartenders = IntegerField()
>
> class Club(Model):
> name = CharField()
> music_style = CharField()
>
> you have a single model that has all the fields:
>
> class Venue(Model):
> name = CharField()
> venuetype = CharField(choices=(('b','bar'),('c','club'))
> number_of_bartenders = IntegerField(null=True)
> music_style = CharField(null=True)
>
> This way you spend a little more time in data validation (making sure
> that you have all the columns that you need for any given row), and
> you waste a little space in the database, but lookups will be a little
> faster (as no joins are required).
>
> Yours,
> Russ Magee %-)
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