diff options
Diffstat (limited to 'django/db/models/sql')
| -rw-r--r-- | django/db/models/sql/datastructures.py | 15 | ||||
| -rw-r--r-- | django/db/models/sql/query.py | 17 |
2 files changed, 30 insertions, 2 deletions
diff --git a/django/db/models/sql/datastructures.py b/django/db/models/sql/datastructures.py index b32148eba5..f45ecaf76d 100644 --- a/django/db/models/sql/datastructures.py +++ b/django/db/models/sql/datastructures.py @@ -4,6 +4,21 @@ the SQL domain. """ +class Col(object): + def __init__(self, alias, col): + self.alias = alias + self.col = col + + def as_sql(self, qn, connection): + return '%s.%s' % (qn(self.alias), self.col), [] + + def prepare(self): + return self + + def relabeled_clone(self, relabels): + return self.__class__(relabels.get(self.alias, self.alias), self.col) + + class EmptyResultSet(Exception): pass diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py index 493856fb41..46a308f5ce 100644 --- a/django/db/models/sql/query.py +++ b/django/db/models/sql/query.py @@ -22,7 +22,7 @@ from django.db.models.related import PathInfo from django.db.models.sql import aggregates as base_aggregates_module from django.db.models.sql.constants import (QUERY_TERMS, ORDER_DIR, SINGLE, ORDER_PATTERN, JoinInfo, SelectInfo) -from django.db.models.sql.datastructures import EmptyResultSet, Empty, MultiJoin +from django.db.models.sql.datastructures import EmptyResultSet, Empty, MultiJoin, Col from django.db.models.sql.expressions import SQLEvaluator from django.db.models.sql.where import (WhereNode, Constraint, EverythingNode, ExtraWhere, AND, OR, EmptyWhere) @@ -820,6 +820,9 @@ class Query(object): conflict. Even tables that previously had no alias will get an alias after this call. """ + if self.alias_prefix != outer_query.alias_prefix: + # No clashes between self and outer query should be possible. + return self.alias_prefix = chr(ord(self.alias_prefix) + 1) while self.alias_prefix in self.subq_aliases: self.alias_prefix = chr(ord(self.alias_prefix) + 1) @@ -1514,9 +1517,19 @@ class Query(object): # since we are adding a IN <subquery> clause. This prevents the # database from tripping over IN (...,NULL,...) selects and returning # nothing + alias, col = query.select[0].col if self.is_nullable(query.select[0].field): - alias, col = query.select[0].col query.where.add((Constraint(alias, col, query.select[0].field), 'isnull', False), AND) + if alias in can_reuse: + pk = query.select[0].field.model._meta.pk + # Need to add a restriction so that outer query's filters are in effect for + # the subquery, too. + query.bump_prefix(self) + query.where.add( + (Constraint(query.select[0].col[0], pk.column, pk), + 'exact', Col(alias, pk.column)), + AND + ) condition = self.build_filter( ('%s__in' % trimmed_prefix, query), |