Fixed #12937 -- Corrected the operation of select_related() when following an reverse relation on an inherited model. Thanks to subsume for the report.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12814 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Russell Keith-Magee 2010-03-20 15:02:59 +00:00
parent 4528f39886
commit bfa080f402
4 changed files with 41 additions and 16 deletions

View File

@ -1113,7 +1113,7 @@ class EmptyQuerySet(QuerySet):
def get_cached_row(klass, row, index_start, using, max_depth=0, cur_depth=0,
requested=None, offset=0, only_load=None):
requested=None, offset=0, only_load=None, local_only=False):
"""
Helper function that recursively returns an object with the specified
related attributes already populated.
@ -1141,6 +1141,8 @@ def get_cached_row(klass, row, index_start, using, max_depth=0, cur_depth=0,
* only_load - if the query has had only() or defer() applied,
this is the list of field names that will be returned. If None,
the full field list for `klass` can be assumed.
* local_only - Only populate local fields. This is used when building
following reverse select-related relations
"""
if max_depth and requested is None and cur_depth > max_depth:
# We've recursed deeply enough; stop now.
@ -1153,9 +1155,11 @@ def get_cached_row(klass, row, index_start, using, max_depth=0, cur_depth=0,
skip = set()
init_list = []
# Build the list of fields that *haven't* been requested
for field in klass._meta.fields:
for field, model in klass._meta.get_fields_with_model():
if field.name not in load_fields:
skip.add(field.name)
elif local_only and model is not None:
continue
else:
init_list.append(field.attname)
# Retrieve all the requested fields
@ -1174,7 +1178,11 @@ def get_cached_row(klass, row, index_start, using, max_depth=0, cur_depth=0,
else:
# Load all fields on klass
field_count = len(klass._meta.fields)
if local_only:
field_names = [f.attname for f in klass._meta.local_fields]
else:
field_names = [f.attname for f in klass._meta.fields]
field_count = len(field_names)
fields = row[index_start : index_start + field_count]
# If all the select_related columns are None, then the related
# object must be non-existent - set the relation to None.
@ -1182,7 +1190,7 @@ def get_cached_row(klass, row, index_start, using, max_depth=0, cur_depth=0,
if fields == (None,) * field_count:
obj = None
else:
obj = klass(*fields)
obj = klass(**dict(zip(field_names, fields)))
# If an object was retrieved, set the database state.
if obj:
@ -1229,7 +1237,7 @@ def get_cached_row(klass, row, index_start, using, max_depth=0, cur_depth=0,
next = requested[f.related_query_name()]
# Recursively retrieve the data for the related object
cached_row = get_cached_row(model, row, index_end, using,
max_depth, cur_depth+1, next)
max_depth, cur_depth+1, next, local_only=True)
# If the recursive descent found an object, populate the
# descriptor caches relevant to the object
if cached_row:
@ -1242,7 +1250,20 @@ def get_cached_row(klass, row, index_start, using, max_depth=0, cur_depth=0,
# If the related object exists, populate
# the descriptor cache.
setattr(rel_obj, f.get_cache_name(), obj)
# Now populate all the non-local field values
# on the related object
for rel_field,rel_model in rel_obj._meta.get_fields_with_model():
if rel_model is not None:
setattr(rel_obj, rel_field.attname, getattr(obj, rel_field.attname))
# populate the field cache for any related object
# that has already been retrieved
if rel_field.rel:
try:
cached_obj = getattr(obj, rel_field.get_cache_name())
setattr(rel_obj, rel_field.get_cache_name(), cached_obj)
except AttributeError:
# Related object hasn't been cached yet
pass
return obj, index_end
def delete_objects(seen_objs, using):

View File

@ -215,7 +215,7 @@ class SQLCompiler(object):
return result
def get_default_columns(self, with_aliases=False, col_aliases=None,
start_alias=None, opts=None, as_pairs=False):
start_alias=None, opts=None, as_pairs=False, local_only=False):
"""
Computes the default columns for selecting every field in the base
model. Will sometimes be called to pull in related models (e.g. via
@ -240,6 +240,8 @@ class SQLCompiler(object):
if start_alias:
seen = {None: start_alias}
for field, model in opts.get_fields_with_model():
if local_only and model is not None:
continue
if start_alias:
try:
alias = seen[model]
@ -643,7 +645,7 @@ class SQLCompiler(object):
)
used.add(alias)
columns, aliases = self.get_default_columns(start_alias=alias,
opts=model._meta, as_pairs=True)
opts=model._meta, as_pairs=True, local_only=True)
self.query.related_select_cols.extend(columns)
self.query.related_select_fields.extend(model._meta.fields)

View File

@ -43,8 +43,7 @@ class StatDetails(models.Model):
class AdvancedUserStat(UserStat):
pass
karma = models.IntegerField()
class Image(models.Model):
name = models.CharField(max_length=100)

View File

@ -22,7 +22,7 @@ class ReverseSelectRelatedTestCase(TestCase):
user2 = User.objects.create(username="bob")
results2 = UserStatResult.objects.create(results='moar results')
advstat = AdvancedUserStat.objects.create(user=user2, posts=200,
advstat = AdvancedUserStat.objects.create(user=user2, posts=200, karma=5,
results=results2)
StatDetails.objects.create(base_stats=advstat, comments=250)
@ -74,13 +74,16 @@ class ReverseSelectRelatedTestCase(TestCase):
self.assertQueries(2)
def test_follow_from_child_class(self):
stat = AdvancedUserStat.objects.select_related("statdetails").get(posts=200)
stat = AdvancedUserStat.objects.select_related('user', 'statdetails').get(posts=200)
self.assertEqual(stat.statdetails.comments, 250)
self.assertEqual(stat.user.username, 'bob')
self.assertQueries(1)
def test_follow_inheritance(self):
stat = UserStat.objects.select_related('advanceduserstat').get(posts=200)
stat = UserStat.objects.select_related('user', 'advanceduserstat').get(posts=200)
self.assertEqual(stat.advanceduserstat.posts, 200)
self.assertEqual(stat.user.username, 'bob')
self.assertEqual(stat.advanceduserstat.user.username, 'bob')
self.assertQueries(1)
def test_nullable_relation(self):