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Code Issues 32 Releases Wiki Activity

queryset-refactor: Fixed the optimization that potentially removes the final

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join to handle the case where a to_field attribute is given for the join.


git-svn-id: http://code.djangoproject.com/svn/django/branches/queryset-refactor@6495 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Malcolm Tredinnick 2007-10-14 02:15:52 +00:00
parent 425e4662a4
commit 240ecf0811
2 changed files with 15 additions and 17 deletions
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14
django/db/models/sql/query.py
View File

@ -576,6 +576,7 @@ class Query(object):
if not null_point and nullable: if not null_point and nullable:
null_point = len(join_list) null_point = len(join_list)
if connection == OR and not split: if connection == OR and not split:
# FIXME: Document what's going on and why this is needed.
if self.alias_map[joins[0]][ALIAS_REFCOUNT] == 1: if self.alias_map[joins[0]][ALIAS_REFCOUNT] == 1:
split = True split = True
self.promote_alias(joins[0]) self.promote_alias(joins[0])
@ -595,13 +596,14 @@ class Query(object):
col = target_col or target_field.column col = target_col or target_field.column
if target_field is opts.pk and join_list: if join_list:
# An optimization: if the final join is against a primary key, # An optimization: if the final join is against the same column as
# we can go back one step in the join chain and compare against # we are comparing against, we can go back one step in the join
# the lhs of the join instead. The result (potentially) involves # chain and compare against the lhs of the join instead. The result
# one less table join. # (potentially) involves one less table join.
self.unref_alias(alias)
join = self.alias_map[join_list[-1][-1]][ALIAS_JOIN] join = self.alias_map[join_list[-1][-1]][ALIAS_JOIN]
if col == join[RHS_JOIN_COL]:
self.unref_alias(alias)
alias = join[LHS_ALIAS] alias = join[LHS_ALIAS]
col = join[LHS_JOIN_COL] col = join[LHS_JOIN_COL]

14
tests/regressiontests/queries/models.py
View File

@ -128,19 +128,15 @@ Bug #2253
>>> (q1 & q2).order_by('name') >>> (q1 & q2).order_by('name')
[<Item: one>] [<Item: one>]
Bugs #4088 & #4306 Bugs #4088, #4306
>>> Report.objects.filter(creator=1001) >>> Report.objects.filter(creator=1001)
[<Report: r1>] [<Report: r1>]
>>> Report.objects.filter(creator__num=1001) >>> Report.objects.filter(creator__num=1001)
[<Report: r1>] [<Report: r1>]
>>> Report.objects.filter(creator__id=1001)
# FIXME: The "removing final pk comparison" optimization is biting us here. []
# Need to only remove it if the join was also on the pk value. >>> Report.objects.filter(creator__id=a1.id)
# >>> Report.objects.filter(creator__id=1001) [<Report: r1>]
# []
# >>> Report.objects.filter(creator__id=a1.id)
# [<Report: r1>]
>>> Report.objects.filter(creator__name='a1') >>> Report.objects.filter(creator__name='a1')
[<Report: r1>] [<Report: r1>]