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This fixes a group of problems in the SQL created by QuerySet.exclude() when

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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
This commit is contained in:
Malcolm Tredinnick
2008-12-08 02:39:51 +00:00
parent d4f0ae42a2
commit 33c0f0de67
2 changed files with 53 additions and 20 deletions
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48
django/db/models/sql/query.py
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@@ -54,7 +54,6 @@ class BaseQuery(object):
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 @@ class BaseQuery(object):
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 @@ class BaseQuery(object):
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 @@ class BaseQuery(object):
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 @@ class BaseQuery(object):
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
select_col = self.alias_map[joins[1]][LHS_JOIN_COL]
select_alias = alias
# 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.
# 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):
"""