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Fixed #10182 -- Corrected realiasing and the process of evaluating va…

…lues() for queries with aggregate clauses. This means that aggregate queries can now be used as subqueries (such as in an __in clause). Thanks to omat for the report.

This involves a slight change to the interaction of annotate() and values() clauses that specify a list of columns. See the docs for details.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@9888 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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commit 542709d0d1796326dd1edacf32fc1198cfad2869 1 parent 4bd2447
@freakboy3742 freakboy3742 authored
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2  django/db/models/aggregates.py
@@ -46,7 +46,7 @@ def add_to_query(self, query, alias, col, source, is_summary):
# Validate that the backend has a fully supported, correct
# implementation of this aggregate
query.connection.ops.check_aggregate_support(aggregate)
- query.aggregate_select[alias] = aggregate
+ query.aggregates[alias] = aggregate
class Avg(Aggregate):
name = 'Avg'
View
16 django/db/models/query.py
@@ -596,7 +596,7 @@ def annotate(self, *args, **kwargs):
obj = self._clone()
- obj._setup_aggregate_query()
+ obj._setup_aggregate_query(kwargs.keys())
# Add the aggregates to the query
for (alias, aggregate_expr) in kwargs.items():
@@ -693,7 +693,7 @@ def _merge_sanity_check(self, other):
"""
pass
- def _setup_aggregate_query(self):
+ def _setup_aggregate_query(self, aggregates):
"""
Prepare the query for computing a result that contains aggregate annotations.
"""
@@ -773,6 +773,8 @@ def _setup_query(self):
self.query.select = []
self.query.add_fields(self.field_names, False)
+ if self.aggregate_names is not None:
+ self.query.set_aggregate_mask(self.aggregate_names)
def _clone(self, klass=None, setup=False, **kwargs):
"""
@@ -798,13 +800,17 @@ def _merge_sanity_check(self, other):
raise TypeError("Merging '%s' classes must involve the same values in each case."
% self.__class__.__name__)
- def _setup_aggregate_query(self):
+ def _setup_aggregate_query(self, aggregates):
"""
Prepare the query for computing a result that contains aggregate annotations.
"""
self.query.set_group_by()
- super(ValuesQuerySet, self)._setup_aggregate_query()
+ if self.aggregate_names is not None:
+ self.aggregate_names.extend(aggregates)
+ self.query.set_aggregate_mask(self.aggregate_names)
+
+ super(ValuesQuerySet, self)._setup_aggregate_query(aggregates)
def as_sql(self):
"""
@@ -824,6 +830,7 @@ class ValuesListQuerySet(ValuesQuerySet):
def iterator(self):
if self.extra_names is not None:
self.query.trim_extra_select(self.extra_names)
+
if self.flat and len(self._fields) == 1:
for row in self.query.results_iter():
yield row[0]
@@ -837,6 +844,7 @@ def iterator(self):
extra_names = self.query.extra_select.keys()
field_names = self.field_names
aggregate_names = self.query.aggregate_select.keys()
+
names = extra_names + field_names + aggregate_names
# If a field list has been specified, use it. Otherwise, use the
View
70 django/db/models/sql/query.py
@@ -77,7 +77,9 @@ def __init__(self, model, connection, where=WhereNode):
self.related_select_cols = []
# SQL aggregate-related attributes
- self.aggregate_select = SortedDict() # Maps alias -> SQL aggregate function
+ self.aggregates = SortedDict() # Maps alias -> SQL aggregate function
+ self.aggregate_select_mask = None
+ self._aggregate_select_cache = None
# Arbitrary maximum limit for select_related. Prevents infinite
# recursion. Can be changed by the depth parameter to select_related().
@@ -187,7 +189,15 @@ def clone(self, klass=None, **kwargs):
obj.distinct = self.distinct
obj.select_related = self.select_related
obj.related_select_cols = []
- obj.aggregate_select = self.aggregate_select.copy()
+ obj.aggregates = self.aggregates.copy()
+ if self.aggregate_select_mask is None:
+ obj.aggregate_select_mask = None
+ else:
+ obj.aggregate_select_mask = self.aggregate_select_mask[:]
+ if self._aggregate_select_cache is None:
+ obj._aggregate_select_cache = None
+ else:
+ obj._aggregate_select_cache = self._aggregate_select_cache.copy()
obj.max_depth = self.max_depth
obj.extra_select = self.extra_select.copy()
obj.extra_tables = self.extra_tables
@@ -940,14 +950,17 @@ def change_aliases(self, change_map):
"""
assert set(change_map.keys()).intersection(set(change_map.values())) == set()
- # 1. Update references in "select" and "where".
+ # 1. Update references in "select" (normal columns plus aliases),
+ # "group by", "where" and "having".
self.where.relabel_aliases(change_map)
- for pos, col in enumerate(self.select):
- if isinstance(col, (list, tuple)):
- old_alias = col[0]
- self.select[pos] = (change_map.get(old_alias, old_alias), col[1])
- else:
- col.relabel_aliases(change_map)
+ self.having.relabel_aliases(change_map)
+ for columns in (self.select, self.aggregates.values(), self.group_by or []):
+ for pos, col in enumerate(columns):
+ if isinstance(col, (list, tuple)):
+ old_alias = col[0]
+ columns[pos] = (change_map.get(old_alias, old_alias), col[1])
+ else:
+ col.relabel_aliases(change_map)
# 2. Rename the alias in the internal table/alias datastructures.
for old_alias, new_alias in change_map.iteritems():
@@ -1205,11 +1218,11 @@ def add_aggregate(self, aggregate, model, alias, is_summary):
opts = model._meta
field_list = aggregate.lookup.split(LOOKUP_SEP)
if (len(field_list) == 1 and
- aggregate.lookup in self.aggregate_select.keys()):
+ aggregate.lookup in self.aggregates.keys()):
# Aggregate is over an annotation
field_name = field_list[0]
col = field_name
- source = self.aggregate_select[field_name]
+ source = self.aggregates[field_name]
elif (len(field_list) > 1 or
field_list[0] not in [i.name for i in opts.fields]):
field, source, opts, join_list, last, _ = self.setup_joins(
@@ -1299,7 +1312,7 @@ def add_filter(self, filter_expr, connector=AND, negate=False, trim=False,
value = SQLEvaluator(value, self)
having_clause = value.contains_aggregate
- for alias, aggregate in self.aggregate_select.items():
+ for alias, aggregate in self.aggregates.items():
if alias == parts[0]:
entry = self.where_class()
entry.add((aggregate, lookup_type, value), AND)
@@ -1824,8 +1837,8 @@ def set_group_by(self):
self.group_by = []
if self.connection.features.allows_group_by_pk:
if len(self.select) == len(self.model._meta.fields):
- self.group_by.append('.'.join([self.model._meta.db_table,
- self.model._meta.pk.column]))
+ self.group_by.append((self.model._meta.db_table,
+ self.model._meta.pk.column))
return
for sel in self.select:
@@ -1858,7 +1871,11 @@ def add_count_column(self):
# Distinct handling is done in Count(), so don't do it at this
# level.
self.distinct = False
- self.aggregate_select = {None: count}
+
+ # Set only aggregate to be the count column.
+ # Clear out the select cache to reflect the new unmasked aggregates.
+ self.aggregates = {None: count}
+ self.set_aggregate_mask(None)
def add_select_related(self, fields):
"""
@@ -1920,6 +1937,29 @@ def trim_extra_select(self, names):
for key in set(self.extra_select).difference(set(names)):
del self.extra_select[key]
+ def set_aggregate_mask(self, names):
+ "Set the mask of aggregates that will actually be returned by the SELECT"
+ self.aggregate_select_mask = names
+ self._aggregate_select_cache = None
+
+ def _aggregate_select(self):
+ """The SortedDict of aggregate columns that are not masked, and should
+ be used in the SELECT clause.
+
+ This result is cached for optimization purposes.
+ """
+ if self._aggregate_select_cache is not None:
+ return self._aggregate_select_cache
+ elif self.aggregate_select_mask is not None:
+ self._aggregate_select_cache = SortedDict([
+ (k,v) for k,v in self.aggregates.items()
+ if k in self.aggregate_select_mask
+ ])
+ return self._aggregate_select_cache
+ else:
+ return self.aggregates
+ aggregate_select = property(_aggregate_select)
+
def set_start(self, start):
"""
Sets the table from which to start joining. The start position is
View
12 django/db/models/sql/where.py
@@ -213,10 +213,14 @@ def relabel_aliases(self, change_map, node=None):
elif isinstance(child, tree.Node):
self.relabel_aliases(change_map, child)
else:
- elt = list(child[0])
- if elt[0] in change_map:
- elt[0] = change_map[elt[0]]
- node.children[pos] = (tuple(elt),) + child[1:]
+ if isinstance(child[0], (list, tuple)):
+ elt = list(child[0])
+ if elt[0] in change_map:
+ elt[0] = change_map[elt[0]]
+ node.children[pos] = (tuple(elt),) + child[1:]
+ else:
+ child[0].relabel_aliases(change_map)
+
# Check if the query value also requires relabelling
if hasattr(child[3], 'relabel_aliases'):
child[3].relabel_aliases(change_map)
View
14 docs/topics/db/aggregation.txt
@@ -284,9 +284,6 @@ two authors with the same name, their results will be merged into a single
result in the output of the query; the average will be computed as the
average over the books written by both authors.
-The annotation name will be added to the fields returned
-as part of the ``ValuesQuerySet``.
-
Order of ``annotate()`` and ``values()`` clauses
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -303,12 +300,21 @@ output.
For example, if we reverse the order of the ``values()`` and ``annotate()``
clause from our previous example::
- >>> Author.objects.annotate(average_rating=Avg('book__rating')).values('name')
+ >>> Author.objects.annotate(average_rating=Avg('book__rating')).values('name', 'average_rating')
This will now yield one unique result for each author; however, only
the author's name and the ``average_rating`` annotation will be returned
in the output data.
+You should also note that ``average_rating`` has been explicitly included
+in the list of values to be returned. This is required because of the
+ordering of the ``values()`` and ``annotate()`` clause.
+
+If the ``values()`` clause precedes the ``annotate()`` clause, any annotations
+will be automatically added to the result set. However, if the ``values()``
+clause is applied after the ``annotate()`` clause, you need to explicitly
+include the aggregate column.
+
Aggregating annotations
-----------------------
View
5 tests/modeltests/aggregation/models.py
@@ -207,10 +207,9 @@ class Clues(models.Model):
>>> Book.objects.filter(pk=1).annotate(mean_age=Avg('authors__age')).values('pk', 'isbn', 'mean_age')
[{'pk': 1, 'isbn': u'159059725', 'mean_age': 34.5}]
-# Calling it with paramters reduces the output but does not remove the
-# annotation.
+# Calling values() with parameters reduces the output
>>> Book.objects.filter(pk=1).annotate(mean_age=Avg('authors__age')).values('name')
-[{'name': u'The Definitive Guide to Django: Web Development Done Right', 'mean_age': 34.5}]
+[{'name': u'The Definitive Guide to Django: Web Development Done Right'}]
# An empty values() call before annotating has the same effect as an
# empty values() call after annotating
View
15 tests/regressiontests/aggregation_regress/models.py
@@ -95,10 +95,18 @@ def __unicode__(self):
>>> sorted(Book.objects.all().values().annotate(mean_auth_age=Avg('authors__age')).extra(select={'manufacture_cost' : 'price * .5'}).get(pk=2).items())
[('contact_id', 3), ('id', 2), ('isbn', u'067232959'), ('manufacture_cost', ...11.545...), ('mean_auth_age', 45.0), ('name', u'Sams Teach Yourself Django in 24 Hours'), ('pages', 528), ('price', Decimal("23.09")), ('pubdate', datetime.date(2008, 3, 3)), ('publisher_id', 2), ('rating', 3.0)]
-# A values query that selects specific columns reduces the output
+# If the annotation precedes the values clause, it won't be included
+# unless it is explicitly named
>>> sorted(Book.objects.all().annotate(mean_auth_age=Avg('authors__age')).extra(select={'price_per_page' : 'price / pages'}).values('name').get(pk=1).items())
+[('name', u'The Definitive Guide to Django: Web Development Done Right')]
+
+>>> sorted(Book.objects.all().annotate(mean_auth_age=Avg('authors__age')).extra(select={'price_per_page' : 'price / pages'}).values('name','mean_auth_age').get(pk=1).items())
[('mean_auth_age', 34.5), ('name', u'The Definitive Guide to Django: Web Development Done Right')]
+# If an annotation isn't included in the values, it can still be used in a filter
+>>> Book.objects.annotate(n_authors=Count('authors')).values('name').filter(n_authors__gt=2)
+[{'name': u'Python Web Development with Django'}]
+
# The annotations are added to values output if values() precedes annotate()
>>> sorted(Book.objects.all().values('name').annotate(mean_auth_age=Avg('authors__age')).extra(select={'price_per_page' : 'price / pages'}).get(pk=1).items())
[('mean_auth_age', 34.5), ('name', u'The Definitive Guide to Django: Web Development Done Right')]
@@ -207,6 +215,11 @@ def __unicode__(self):
>>> Book.objects.extra(select={'pub':'publisher_id','foo':'pages'}).values('pub').annotate(Count('id')).order_by('pub')
[{'pub': 1, 'id__count': 2}, {'pub': 2, 'id__count': 1}, {'pub': 3, 'id__count': 2}, {'pub': 4, 'id__count': 1}]
+# Regression for #10182 - Queries with aggregate calls are correctly realiased when used in a subquery
+>>> ids = Book.objects.filter(pages__gt=100).annotate(n_authors=Count('authors')).filter(n_authors__gt=2).order_by('n_authors')
+>>> Book.objects.filter(id__in=ids)
+[<Book: Python Web Development with Django>]
+
# Regression for #10199 - Aggregate calls clone the original query so the original query can still be used
>>> books = Book.objects.all()
>>> _ = books.aggregate(Avg('authors__age'))
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