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This fixes a group of problems in the SQL created by QuerySet.exclude…

…() when

used in a few situations where NULL results can appear.

Fixed #8921 (the only ticket I know of that noticed any of these).


git-svn-id: http://code.djangoproject.com/svn/django/trunk@9590 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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commit 33c0f0de676ae8fd2c406beebb2f113aeb95fee7 1 parent d4f0ae4
Malcolm Tredinnick malcolmt authored
50 django/db/models/sql/query.py
View
@@ -54,7 +54,6 @@ def __init__(self, model, connection, where=WhereNode):
self.default_ordering = True
self.standard_ordering = True
self.ordering_aliases = []
- self.start_meta = None
self.select_fields = []
self.related_select_fields = []
self.dupe_avoidance = {}
@@ -125,10 +124,9 @@ def __setstate__(self, obj_dict):
def get_meta(self):
"""
Returns the Options instance (the model._meta) from which to start
- processing. Normally, this is self.model._meta, but it can change.
+ processing. Normally, this is self.model._meta, but it can be changed
+ by subclasses.
"""
- if self.start_meta:
- return self.start_meta
return self.model._meta
def quote_name_unless_alias(self, name):
@@ -166,7 +164,6 @@ def clone(self, klass=None, **kwargs):
obj.default_ordering = self.default_ordering
obj.standard_ordering = self.standard_ordering
obj.ordering_aliases = []
- obj.start_meta = self.start_meta
obj.select_fields = self.select_fields[:]
obj.related_select_fields = self.related_select_fields[:]
obj.dupe_avoidance = self.dupe_avoidance.copy()
@@ -1485,11 +1482,24 @@ def split_exclude(self, filter_expr, prefix, can_reuse):
query = Query(self.model, self.connection)
query.add_filter(filter_expr, can_reuse=can_reuse)
query.bump_prefix()
- query.set_start(prefix)
query.clear_ordering(True)
+ query.set_start(prefix)
self.add_filter(('%s__in' % prefix, query), negate=True, trim=True,
can_reuse=can_reuse)
+ # If there's more than one join in the inner query (before any initial
+ # bits were trimmed -- which means the last active table is more than
+ # two places into the alias list), we need to also handle the
+ # possibility that the earlier joins don't match anything by adding a
+ # comparison to NULL (e.g. in
+ # Tag.objects.exclude(parent__parent__name='t1'), a tag with no parent
+ # would otherwise be overlooked).
+ active_positions = [pos for (pos, count) in
+ enumerate(query.alias_refcount.itervalues()) if count]
+ if active_positions[-1] > 1:
+ self.add_filter(('%s__isnull' % prefix, False), negate=True,
+ trim=True, can_reuse=can_reuse)
+
def set_limits(self, low=None, high=None):
"""
Adjusts the limits on the rows retrieved. We use low/high to set these,
@@ -1695,18 +1705,26 @@ def set_start(self, start):
alias = self.get_initial_alias()
field, col, opts, joins, last, extra = self.setup_joins(
start.split(LOOKUP_SEP), opts, alias, False)
- alias = joins[last[-1]]
- self.select = [(alias, self.alias_map[alias][RHS_JOIN_COL])]
- self.select_fields = [field]
- self.start_meta = opts
-
- # The call to setup_joins add an extra reference to everything in
- # joins. So we need to unref everything once, and everything prior to
- # the final join a second time.
+ select_col = self.alias_map[joins[1]][LHS_JOIN_COL]
+ select_alias = alias
+
+ # The call to setup_joins added an extra reference to everything in
+ # joins. Reverse that.
for alias in joins:
self.unref_alias(alias)
- for alias in joins[:last[-1]]:
- self.unref_alias(alias)
+
+ # We might be able to trim some joins from the front of this query,
+ # providing that we only traverse "always equal" connections (i.e. rhs
+ # is *always* the same value as lhs).
+ for alias in joins[1:]:
+ join_info = self.alias_map[alias]
+ if (join_info[LHS_JOIN_COL] != select_col
+ or join_info[JOIN_TYPE] != self.INNER):
+ break
+ self.unref_alias(select_alias)
+ select_alias = join_info[RHS_ALIAS]
+ select_col = join_info[RHS_JOIN_COL]
+ self.select = [(select_alias, select_col)]
def execute_sql(self, result_type=MULTI):
"""
25 tests/regressiontests/queries/models.py
View
@@ -675,7 +675,7 @@ class PointerB(models.Model):
... s.reverse()
... params.reverse()
-# This slightly odd comparison works aorund the fact that PostgreSQL will
+# This slightly odd comparison works around the fact that PostgreSQL will
# return 'one' and 'two' as strings, not Unicode objects. It's a side-effect of
# using constants here and not a real concern.
>>> d = Item.objects.extra(select=SortedDict(s), select_params=params).values('a', 'b')[0]
@@ -742,7 +742,7 @@ class PointerB(models.Model):
## only apparent much later when the full test suite runs. I don't understand
## what's going on here yet.
##
-## # We need to mess with the implemenation internals a bit here to decrease the
+## # We need to mess with the implementation internals a bit here to decrease the
## # cache fill size so that we don't read all the results at once.
## >>> from django.db.models import query
## >>> query.ITER_CHUNK_SIZE = 2
@@ -795,7 +795,7 @@ class PointerB(models.Model):
[<Item: four>, <Item: one>, <Item: three>]
Bug #7095
-Updates that are filtered on the model being updated are somewhat tricky to get
+Updates that are filtered on the model being updated are somewhat tricky
in MySQL. This exercises that case.
>>> mm = ManagedModel.objects.create(data='mm1', tag=t1, public=True)
>>> ManagedModel.objects.update(data='mm')
@@ -998,13 +998,28 @@ class PointerB(models.Model):
>>> 'ORDER BY' in qs.query.as_sql()[0]
True
-Bug #9188 -- incorrect SQL was being generated for certain types of
-exclude() queries that crossed multi-valued relations.
+Incorrect SQL was being generated for certain types of exclude() queries that
+crossed multi-valued relations (#8921, #9188 and some pre-emptively discovered
+cases).
>>> PointerA.objects.filter(connection__pointerb__id=1)
[]
>>> PointerA.objects.exclude(connection__pointerb__id=1)
[]
+
+>>> Tag.objects.exclude(children=None)
+[<Tag: t1>, <Tag: t3>]
+
+# This example is tricky because the parent could be NULL, so only checking
+# parents with annotations omits some results (tag t1, in this case).
+>>> Tag.objects.exclude(parent__annotation__name="a1")
+[<Tag: t1>, <Tag: t4>, <Tag: t5>]
+
+# The annotation->tag link is single values and tag->children links is
+# multi-valued. So we have to split the exclude filter in the middle and then
+# optimise the inner query without losing results.
+>>> Annotation.objects.exclude(tag__children__name="t2")
+[<Annotation: a2>]
"""}
# In Python 2.3 and the Python 2.6 beta releases, exceptions raised in __len__
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