Thanks, but damn, isn't that overly complicated (for me). Using through
looks like a easier way, but then I have to add Wheel four times and can't
just type '4' in some field, since I don't need it to exist in database
four time, just an information that there are four wheels.
W dniu piątek, 6 lipca 2012 16:43:27 UTC+2 użytkownik Tomas Neme napisał:
>
> > I don't understand. It's the same wheel added four times, not four
> > different wheels.
>
> I guess you could implement it either way. The thing is that doing it
> this way would become complicated at the time you need to define what
> is attached where. For Lego pieces, I'd do this:
>
> class LegoType(Model) has a description, maybe a picture, and it's
> behavior
>
> model LegoPiece has a ForeignKey(LegoType), a ManyToMany to other
> LegoPieces (the ones it's connected to).
>
> You'd have one LegoType = wheel, and four LegoPiece who's type would
> be wheel. When you defined the Type you'd need a way to link each
> model to specific python code that controlled how many pieces it can
> connect to, and how, but that's a song for another day.
>
> Then you do LegoPiece.objects.filter(type__name="wheel").count(), and
> voila, you have how many wheels you have.
>
> You COULD have enough knowing the amount of pieces of each kind you
> have, you'd be modeling something similar to an inventory, but
> defining connections in that context would be unnecessarily
> complicated, since you'd not only have to count how many pieces you
> have of each type, but when you connect one to another, *which one*
> are you connecting? one that's free, or one that's connected to
> another one? How would you model the connections? Say one brick can
> connect to as many as 8 other pieces, 4 on each side, say you have 3
> bricks, so you know you can't have more than 24 connecctions, but..
> how do you differentiate between A--B C--D--E and A--B--C--D or.. I
> don't know how to draw it, but D--A--B D--A--C (A is connected to D on
> one side, and to B and C both on the other).
>
> It might be that you can model your needs this way, but AFAICS, it'd
> be a lot harder to follow things and keep things consistent in an
> Object Oriented way.
>
> --
> "The whole of Japan is pure invention. There is no such country, there are
> no such people" --Oscar Wilde
>
> |_|0|_|
> |_|_|0|
> |0|0|0|
>
> (\__/)
> (='.'=)This is Bunny. Copy and paste bunny
> (")_(") to help him gain world domination.
>
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