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
12402	QuerySet.defer does not work properly on Oracle	Jani Tiainen	jbronn	"The machinery in `OracleQuery.resolve_columns` does not take into account any fields that are deferred.  Seeing this error depends on the order of the fields, and how they are handled by `OracleQuery.convert_values` -- which is probably why it's missed in the test suite.  Here's an example model that demonstrates the problem:

{{{
#!python
from django.db import models

class MyModel(models.Model):
     num = models.FloatField()
     name = models.CharField(max_length=128)

}}}

Here's how to raise it:
{{{
>>> MyModel.objects.create(num=5.0, name='Foobar')
<MyModel: MyModel object>
>>> qs = MyModel.objects.defer('num')
>>> print qs
Traceback (most recent call last):
  File ""<ipython console>"", line 1, in <module>
  File ""C:\Python25\lib\site-packages\IPython\Prompts.py"", line 552, in __call__
    manipulated_val = self.display(arg)
  File ""C:\Python25\lib\site-packages\IPython\Prompts.py"", line 578, in _display
    return self.shell.hooks.result_display(arg)
  File ""C:\Python25\lib\site-packages\IPython\hooks.py"", line 141, in __call__
    ret = cmd(*args, **kw)
  File ""C:\Python25\lib\site-packages\IPython\hooks.py"", line 171, in result_display
    out = pformat(arg)
  File ""C:\Python25\lib\pprint.py"", line 111, in pformat
    self._format(object, sio, 0, 0, {}, 0)
  File ""C:\Python25\lib\pprint.py"", line 129, in _format
    rep = self._repr(object, context, level - 1)
  File ""C:\Python25\lib\pprint.py"", line 195, in _repr
    self._depth, level)
  File ""C:\Python25\lib\pprint.py"", line 207, in format
    return _safe_repr(object, context, maxlevels, level)
  File ""C:\Python25\lib\pprint.py"", line 292, in _safe_repr
    rep = repr(object)
  File ""C:\django\trunk\django\db\models\query.py"", line 61, in __repr__
    data = list(self[:REPR_OUTPUT_SIZE + 1])
  File ""C:\django\trunk\django\db\models\query.py"", line 76, in __len__
    self._result_cache.extend(list(self._iter))
  File ""C:\django\trunk\django\db\models\query.py"", line 261, in iterator
    for row in self.query.results_iter():
  File ""C:\django\trunk\django\db\models\sql\query.py"", line 292, in results_iter
    row = self.resolve_columns(row, fields)
  File ""C:\django\trunk\django\db\backends\oracle\query.py"", line 54, in resolve_columns
    values.append(self.convert_values(value, field))
  File ""C:\django\trunk\django\db\backends\oracle\query.py"", line 74, in convert_values
    value = float(value)
ValueError: invalid literal for float(): Foobar
}}}

The problem reveals itself here because although we've deferred the `FloatField`, it's instance is still passed into `convert_values` with the value associated with the `CharField`.

"		assigned	Database layer (models, ORM)	dev			orm oracle defer		Unreviewed	0	0	0	0	0	0