can't use count() on querysets when extra() has been used with params.

[mrmachine <real dot human at mrmachine dot net>]

there seems to be a bug in django/db/models/query.py when using extra() with params on a queryset. the queryset is generated correctly, i can access it, iterate through it, but i can't count() it.

>>> from django.contrib.auth.models import User
>>> u = User.objects.filter(pk=1).extra(select={'foo': '%s'}, params=['1'])
>>> u[0].foo
'1'
>>> u.count()
Traceback (most recent call last):
  File "<console>", line 1, in ?
  File "/Volumes/Singularity/Projects/django/django/db/models/query.py", line 202, in count
    cursor.execute("SELECT COUNT(*)" + sql, params)
  File "/Volumes/Singularity/Projects/django/django/db/backends/util.py", line 19, in execute
    self.db.queries.append({
TypeError: not all arguments converted during string formatting
>>> u = User.objects.filter(pk=1).extra(select={'foo': '1'})
>>> u[0].foo
'1'
>>> u.count()
1

[heckj@…]

I just ran into a similiar situation this evening with the queryset not putting the arguments in the correct ordering, specifically when tacking on two "extra" sets to an otherwise kind of plain jane queryset. I'm trying to work it down to an easily reproducible case or example. In my case, it also appears to be related to using .count() at the tail end of the queryset chain.

If I pull back the queryset, force it into a list, then I can count it - but that sort of defeats the purpose of being able to use the count.

Ah - I narrowed it down to when it's using an extra(select=...) statement. In django/db/models/query.py around line 202, it's invoking:
cursor.execute("SELECT COUNT(*)" + sql, params)

The additional "select" param is added to the list, but the additional "select" component isn't, resulting in the "not all arguments converted" error.

Not sure how to nessecarily resolve this though.

[deepak <deep.thukral@…>]

Main problem is that while logging sql, we are not handling extras in sql queries. I fixed this issue, but needs test.

[amit.ramon@…]

The problem still exists with the latest svn version. It seems to a problem with using select with parameters in extra (extra where with parameters is working fine).

[Malcolm Tredinnick]

(In [7340]) queryset-refactor: Fixed up extra(select=...) calls with parameters so that the
parameters are substituted in correctly in all cases. This introduces an extra
argument to extra() for this purpose; no alternative there.

Also fixed values() to work if you don't specify *all* the extra select aliases
in the values() call.

Refs #3141.

[Malcolm Tredinnick]

(In [7477]) Merged the queryset-refactor branch into trunk.

This is a big internal change, but mostly backwards compatible with existing
code. Also adds a couple of new features.

Fixed #245, #1050, #1656, #1801, #2076, #2091, #2150, #2253, #2306, #2400, #2430, #2482, #2496, #2676, #2737, #2874, #2902, #2939, #3037, #3141, #3288, #3440, #3592, #3739, #4088, #4260, #4289, #4306, #4358, #4464, #4510, #4858, #5012, #5020, #5261, #5295, #5321, #5324, #5325, #5555, #5707, #5796, #5817, #5987, #6018, #6074, #6088, #6154, #6177, #6180, #6203, #6658