Re: [SQLObject] Join tables

[Ian B. <ia...@co...>]

On Nov 10, 2003, at 2:02 AM, John Baker wrote:
> On Monday 10 November 2003 00:57, Ian Bicking wrote:
>>  From a quick inspection of the code, no, that's not implemented.  
>> Yes,
>> it should be.
>
> Goodo. Will it appear in the next version? Should only be a few lines 
> I'd
> guess?

Yes, it should probably go into the next version.

>> Hmm... right now if, say, you have a many-to-one relationship between
>> Replies and Stories, then you have Story.replies.  But that's just a
>> dumb list.  I've thought about an addReply-like method, which would
>> assign the story_id column of Reply.  But I don't quite like it,
>> because you aren't just adding the reply, you are moving it (if it
>> previously had a story).
>
> Yes, that's right, and consistent. It seems rather odd assigning Reply 
> to a
> Story through the new method on Reply ...
>
> Reply.new(... story = s)
>
> That's odder :)
>
> If you think in terms of OO and you're used to Collections, you think 
> about
> adding something to a Collection.

No, it's quite different from a normal collection.  Normal collections 
-- in Python and most other languages -- are many-to-many, i.e., an 
object can be part of multiple collections.  One-to-many relations 
typically imply something more like ownership.

It might be reasonable to "add" a reply to a story if the reply's story 
is already None, but in the more general sense the reply is being 
"moved", not "added".

--
Ian Bicking | ia...@co... | http://blog.ianbicking.org