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Code Issues 32 Releases Wiki Activity

[1.6.x] Fixed #21748 -- join promotion for negated AND conditions

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Made sure Django treats case .filter(NOT (a AND b)) the same way as
.filter((NOT a OR NOT b)) for join promotion.

Heavily modified backpatch of 35cecb1ebd
from master.

Conflicts:

	django/db/models/sql/query.py
	tests/queries/tests.py
This commit is contained in:
Anssi Kääriäinen
2014-01-08 19:35:47 +02:00
parent 0f272629ca
commit fd3fa851b5
2 changed files with 88 additions and 7 deletions
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16
django/db/models/sql/query.py
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@@ -1211,16 +1211,18 @@ class Query(object):
connector = q_object.connector
current_negated = current_negated ^ q_object.negated
branch_negated = branch_negated or q_object.negated
# Note that if the connector happens to match what we have already in
# the tree, the add will be a no-op.
target_clause = self.where_class(connector=connector,
negated=q_object.negated)
if connector == OR:
# Treat case NOT (a AND b) like case ((NOT a) OR (NOT b)) for join
# promotion. See ticket #21748.
effective_connector = connector
if current_negated:
effective_connector = OR if effective_connector == AND else AND
if effective_connector == OR:
alias_usage_counts = dict()
aliases_before = set(self.tables)
for child in q_object.children:
if connector == OR:
if effective_connector == OR:
refcounts_before = self.alias_refcount.copy()
if isinstance(child, Node):
child_clause = self._add_q(
@@ -1231,11 +1233,11 @@ class Query(object):
child, can_reuse=used_aliases, branch_negated=branch_negated,
current_negated=current_negated)
target_clause.add(child_clause, connector)
if connector == OR:
if effective_connector == OR:
used = alias_diff(refcounts_before, self.alias_refcount)
for alias in used:
alias_usage_counts[alias] = alias_usage_counts.get(alias, 0) + 1
if connector == OR:
if effective_connector == OR:
self.promote_disjunction(aliases_before, alias_usage_counts,
len(q_object.children))
return target_clause