id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
8023	Changeset 8131 breaks filtering from the URL in the admin	jdetaeye	Malcolm Tredinnick	"
The admin allows filtering objects by edting the url in the browser window.[[BR]]
Eg: http://youraddress/admin/yourapp/yourmodel/?yourdecimalfield__lt=20

When filtering on a decimal field, changeset #7560 breaks this with the following stacktrace:
{{{
File ""C:\packages\Python-2.5\lib\site-packages\django\core\handlers\base.py"" in get_response
  87.                 response = callback(request, *callback_args, **callback_kwargs)
File ""C:\packages\Python-2.5\lib\site-packages\django\contrib\admin\views\decorators.py"" in _checklogin
  61.             return view_func(request, *args, **kwargs)
File ""c:\develop\frepple\contrib\django\freppledb\utils\report.py"" in view_report
  302.              counter = counter.filter( **{smart_str(key): value} )
File ""C:\packages\Python-2.5\lib\site-packages\django\db\models\query.py"" in filter
  479.         return self._filter_or_exclude(False, *args, **kwargs)
File ""C:\packages\Python-2.5\lib\site-packages\django\db\models\query.py"" in _filter_or_exclude
  497.             clone.query.add_q(Q(*args, **kwargs))
File ""C:\packages\Python-2.5\lib\site-packages\django\db\models\sql\query.py"" in add_q
  1176.                         can_reuse=used_aliases)
File ""C:\packages\Python-2.5\lib\site-packages\django\db\models\sql\query.py"" in add_filter
  1123.         self.where.add((alias, col, field, lookup_type, value), connector)
File ""C:\packages\Python-2.5\lib\site-packages\django\db\models\sql\where.py"" in add
  48.                 params = field.get_db_prep_lookup(lookup_type, value)
File ""C:\packages\Python-2.5\lib\site-packages\django\db\models\fields\__init__.py"" in get_db_prep_lookup
  242.             return [self.get_db_prep_value(value)]
File ""C:\packages\Python-2.5\lib\site-packages\django\db\models\fields\__init__.py"" in get_db_prep_value
  736.                                                   self.decimal_places)
File ""C:\packages\Python-2.5\lib\site-packages\django\db\backends\__init__.py"" in value_to_db_decimal
  302.         return util.format_number(value, max_digits, decimal_places)
File ""C:\packages\Python-2.5\lib\site-packages\django\db\backends\util.py"" in format_number
  126.     return u""%.*f"" % (decimal_places, value)

Exception Type: TypeError at /admin/input/buffer/
Exception Value: a float is required
}}}

The value argument is a Unicode string while the format string only accepts a float.

You can also reproduce the same error from the command line:
{{{
>>> works_as_expected = yourapp.yourmodel.objects.all().filter(yourdecimalfield__gt=0)
>>> doesnt_work_any_more = yourapp.yourmodel.objects.all().filter(yourdecimalfield__gt=u'0')
}}}

Changing the format string from %f to %s fixes the problem in both backends I tested (SQLite + PostgreSQL):
{{{
return u""%.*f"" % (decimal_places, value) # OLD
return u""%.*s"" % (decimal_places, value) # NEW
}}}
"		closed	Database layer (models, ORM)	dev		fixed		johan.de.taeye@…	Unreviewed	0	0	0	0	0	0