Thanks for letting me know. I was afraid I was missing something
obvious.
On Oct 4, 5:48 am, Malcolm Tredinnick <[EMAIL PROTECTED]>
wrote:
> On Wed, 2007-10-03 at 22:44 +0000, tzeskimo wrote:
> > I'm trying to write a custom QuerySet, but I'm a bit confused about
> > how to properly use the method extra(). From my understanding,
> > extra() accepts both "select" and "where" arguments, both of which can
> > contain bind variables. You then pass the appropriate bind variable
> > values to the "param" argument.
>
> > This method seems like it will fall apart if two QuerySets are chained
> > together, both of which pass "select" and "where" arguments to extra.
> > For example, wouldn't the following cause an issue:
>
> > class FooQuerySet:
>
> > def query1(self):
>
> > self.extra(select = {'something': "item * %s"}, where = "item
> > < %s", params = (3, 5))
>
> > def query2(self):
>
> > self.extra(select = {'something_else': "item / %s"}, where =
> > "item > %s", params = (3, 5))
>
> > model.custom_manager.all().query1().query2()
>
> The "select" portion of extra() was never really intended to support
> parameters. There are bigger problems than the one you've noticed here:
> since "select" is a dictionary, it's ordering is indeterminate and so
> when you have multiple items in the dictionary, there is no way to
> reliably map the parameters to those items.
>
> I've been toying with a couple of ideas in the context of the
> queryset-refactor branch to possibly try and make this work (with a
> little more effort on the side of the programmer), but it's never going
> to be particularly neat and tidy.
>
> For now, you can't do that. It's unsupported. You will need to write
> custom SQL.
>
> Regards,
> Malcolm
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