On Mar 21, 2011, at 12:20 PM, Jacob Kaplan-Moss wrote:
> I think we're talking slightly different concerns here: I'm mostly
> interested in the Python-side API, and to my eyes a composite field
> matches more closely what's happening on the Python side of things.
I agree 100%! I think I'm just drawing a different conclusion from that point,
which is that indexes are more metadata on the database rather than a critical
part of the Python API: In an imaginary perfect database (like, say, the SQL
spec envisions), we wouldn't need to talk about indexes as all.
The more I think about it, the less I like including this directly in the field
declaration part of the model, including my Index type proposal. It just
doesn't seem to belong there.
What concerns me about composite fields is that they seem to be a lot of Python
machinery just to accomplish the goal of allowing this annotation. If they
were super-useful in their own right, that would be one thing, but I'm not sure
that I see the utility of them absent indexes and foreign keys. I'm also
bothered, perhaps excessively, about having two different ways of getting at
the same field in the model just to support this.
So, another proposal:
In the foreign key case, just extending the ForeignKey syntax to allow for
multiple related fields makes the most sense:
overThere = models.ForeignKey(OtherModel, to_field=('first_name',
'last_name', ))
For indexes on the table for the model, include the declaration in the Meta
class, since that's the obvious place to stick indexing:
class SomeModel:
class Meta:
primary_key = 'some_field'
indexes = ['some_field', 'some_other_field', ('field1',
'-field2', ), ]
raw_indexes = [ 'some_invariant_function(some_field)' ]
(This was proposed by someone else, and isn't original to me; apologies that I
can't find the email to give credit.)
Of course, the existing syntax would still work as a shortcut for primary_key
and indexes.
Thoughts?
--
-- Christophe Pettus
x...@thebuild.com
--
You received this message because you are subscribed to the Google Groups
"Django developers" group.
To post to this group, send email to django-developers@googlegroups.com.
To unsubscribe from this group, send email to
django-developers+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/django-developers?hl=en.
