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Fixed #9997 -- Fixed use of ValuesQuerySets as rvalues in filters.

Previous behaviour was pretty stupid. Let's never speak of it again. New
behaviour both works and is documented.

git-svn-id: bcc190cf-cafb-0310-a4f2-bffc1f526a37
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1 parent 14b3f03 commit d579e716fef9f06f04861815cf949630d8633271 @malcolmt malcolmt committed Jan 16, 2009
Showing with 46 additions and 0 deletions.
  1. +14 −0 django/db/models/
  2. +16 −0 docs/ref/models/querysets.txt
  3. +16 −0 tests/regressiontests/queries/
@@ -798,6 +798,20 @@ def _setup_aggregate_query(self):
super(ValuesQuerySet, self)._setup_aggregate_query()
+ def as_sql(self):
+ """
+ For ValueQuerySet (and subclasses like ValuesListQuerySet), they can
+ only be used as nested queries if they're already set up to select only
+ a single field (in which case, that is the field column that is
+ returned). This differs from QuerySet.as_sql(), where the column to
+ select is set up by Django.
+ """
+ if ((self._fields and len(self._fields) > 1) or
+ (not self._fields and len(self.model._meta.fields) > 1)):
+ raise TypeError('Cannot use a multi-field %s as a filter value.'
+ % self.__class__.__name__)
+ return self._clone().query.as_nested_sql()
class ValuesListQuerySet(ValuesQuerySet):
def iterator(self):
@@ -1136,6 +1136,7 @@ The above code fragment could also be written as follows::
inner_q = Blog.objects.filter(name__contains='Cheddar').values('pk').query
entries = Entry.objects.filter(blog__in=inner_q)
.. versionchanged:: 1.1
In Django 1.0, only the latter piece of code is valid.
@@ -1144,6 +1145,21 @@ accesses the internal ``query`` attribute and requires a ``ValuesQuerySet``.
If your code doesn't require compatibility with Django 1.0, use the first
form, passing in a queryset directly.
+If you pass in a ``ValuesQuerySet`` or ``ValuesListQuerySet`` (the result of
+calling ``values()`` or ``values_list()`` on a queryset) as the value to an
+``__in`` lookup, you need to ensure you are only extracting one field in the
+result. For example, this will work (filtering on the blog names)::
+ inner_qs = Blog.objects.filter(name__contains='Ch').values('name')
+ entries = Entry.objects.filter(blog__name__in=inner_qs)
+This example will raise an exception, since the inner query is trying to
+extract two field values, where only one is expected::
+ # Bad code! Will raise a TypeError.
+ inner_qs = Blog.objects.filter(name__contains='Ch').values('name', 'id')
+ entries = Entry.objects.filter(blog__name__in=inner_qs)
.. warning::
This ``query`` attribute should be considered an opaque internal attribute.
@@ -1022,6 +1022,22 @@ class PointerB(models.Model):
>>> print Annotation.objects.filter(notes__in=Note.objects.filter(note="xyzzy")).query
+Bug #9997 -- If a ValuesList or Values queryset is passed as an inner query, we
+make sure it's only requesting a single value and use that as the thing to
+>>> Tag.objects.filter(name__in=Tag.objects.filter(parent=t1).values('name'))
+[<Tag: t2>, <Tag: t3>]
+# Multi-valued values() and values_list() querysets should raise errors.
+>>> Tag.objects.filter(name__in=Tag.objects.filter(parent=t1).values('name', 'id'))
+Traceback (most recent call last):
+TypeError: Cannot use a multi-field ValuesQuerySet as a filter value.
+>>> Tag.objects.filter(name__in=Tag.objects.filter(parent=t1).values_list('name', 'id'))
+Traceback (most recent call last):
+TypeError: Cannot use a multi-field ValuesListQuerySet as a filter value.
Bug #9985 -- qs.values_list(...).values(...) combinations should work.
>>> Note.objects.values_list("note", flat=True).values("id").order_by("id")
[{'id': 1}, {'id': 2}, {'id': 3}]

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