Fixed #24687 -- Added select_related() validation for nested non-relational fields.

The removed test was added in the original select_related() validation
patch (45d4e43d2d), but there doesn't
seem to be any reason for it.

Thanks Claude Paroz for help and review.

django/contrib/gis/db/models/query.py

@@ -10,6 +10,7 @@ from django.contrib.gis.db.models.sql import (
 from django.contrib.gis.geometry.backend import Geometry
 from django.contrib.gis.measure import Area, Distance
 from django.db import connections
+from django.db.models.constants import LOOKUP_SEP
 from django.db.models.expressions import RawSQL
 from django.db.models.fields import Field
 from django.db.models.query import QuerySet
@@ -675,9 +676,10 @@ class GeoQuerySet(QuerySet):
         if geo_field not in opts.fields:
             # Is this operation going to be on a related geographic field?
             # If so, it'll have to be added to the select related information
-            # (e.g., if 'location__point' was given as the field name).
+            # (e.g., if 'location__point' was given as the field name, then
+            # chop the non-relational field and add select_related('location')).
             # Note: the operation really is defined as "must add select related!"
-            self.query.add_select_related([field_name])
+            self.query.add_select_related([field_name.rsplit(LOOKUP_SEP, 1)[0]])
             # Call pre_sql_setup() so that compiler.select gets populated.
             compiler.pre_sql_setup()
             for col, _, _ in compiler.select:

django/db/models/sql/compiler.py

@@ -673,7 +673,7 @@ class SQLCompiler(object):
                 if not f.is_relation:
                     # If a non-related field is used like a relation,
                     # or if a single non-relational field is given.
-                    if next or (cur_depth == 1 and f.name in requested):
+                    if next or f.name in requested:
                         raise FieldError(
                             "Non-relational field given in select_related: '%s'. "
                             "Choices are: %s" % (

docs/releases/1.10.txt

@@ -217,6 +217,23 @@ Database backend API
 
 * ...
 
+``select_related()`` prohibits non-relational fields for nested relations
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Django 1.8 added validation for non-relational fields in ``select_related()``::
+
+    >>> Book.objects.select_related('title')
+    Traceback (most recent call last):
+    ...
+    FieldError: Non-relational field given in select_related: 'title'
+
+But it didn't prohibit nested non-relation fields as it does now::
+
+    >>> Book.objects.select_related('author__name')
+    Traceback (most recent call last):
+    ...
+    FieldError: Non-relational field given in select_related: 'name'
+
 Miscellaneous
 ~~~~~~~~~~~~~
 

tests/admin_changelist/admin.py

@@ -36,7 +36,7 @@ class ChildAdmin(admin.ModelAdmin):
     list_filter = ['parent', 'age']
 
     def get_queryset(self, request):
-        return super(ChildAdmin, self).get_queryset(request).select_related("parent__name")
+        return super(ChildAdmin, self).get_queryset(request).select_related("parent")
 
 
 class CustomPaginationAdmin(ChildAdmin):

tests/admin_changelist/tests.py

@@ -75,9 +75,7 @@ class ChangeListTests(TestCase):
             request, Child,
             *get_changelist_args(m, list_select_related=m.get_list_select_related(request))
         )
-        self.assertEqual(cl.queryset.query.select_related, {
+        self.assertEqual(cl.queryset.query.select_related, {'parent': {}})
-            'parent': {'name': {}}
-        })
 
     def test_select_related_as_tuple(self):
         ia = InvitationAdmin(Invitation, custom_site)

tests/gis_tests/relatedapp/tests.py

@@ -62,6 +62,9 @@ class RelatedGeoModelTest(TestCase):
             qs = list(City.objects.filter(name=name).transform(srid, field_name='location__point'))
             check_pnt(GEOSGeometry(wkt, srid), qs[0].location.point)
 
+        # Relations more than one level deep can be queried.
+        self.assertEqual(list(Parcel.objects.transform(srid, field_name='city__location__point')), [])
+
     @skipUnlessDBFeature("supports_extent_aggr")
     def test_related_extent_aggregate(self):
         "Testing the `Extent` aggregate on related geographic models."

tests/select_related/tests.py

@@ -134,12 +134,6 @@ class SelectRelatedTests(TestCase):
             orders = [o.genus.family.order.name for o in world]
             self.assertEqual(orders, ['Agaricales'])
 
-    def test_single_related_field(self):
-        with self.assertNumQueries(1):
-            species = Species.objects.select_related('genus__name')
-            names = [s.genus.name for s in species]
-            self.assertEqual(sorted(names), ['Amanita', 'Drosophila', 'Homo', 'Pisum'])
-
     def test_field_traversal(self):
         with self.assertNumQueries(1):
             s = (Species.objects.all()
@@ -206,6 +200,10 @@ class SelectRelatedValidationTests(SimpleTestCase):
         with self.assertRaisesMessage(FieldError, self.non_relational_error % ('name', '(none)')):
             list(Domain.objects.select_related('name'))
 
+    def test_non_relational_field_nested(self):
+        with self.assertRaisesMessage(FieldError, self.non_relational_error % ('name', 'family')):
+            list(Species.objects.select_related('genus__name'))
+
     def test_many_to_many_field(self):
         with self.assertRaisesMessage(FieldError, self.invalid_error % ('toppings', '(none)')):
             list(Pizza.objects.select_related('toppings'))