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-rw-r--r--django/db/models/sql/where.py39
1 files changed, 30 insertions, 9 deletions
diff --git a/django/db/models/sql/where.py b/django/db/models/sql/where.py
index 18e4bf2f7e..662d99a4a2 100644
--- a/django/db/models/sql/where.py
+++ b/django/db/models/sql/where.py
@@ -35,20 +35,30 @@ class WhereNode(tree.Node):
storing any reference to field objects). Otherwise, the 'data' is
stored unchanged and can be anything with an 'as_sql()' method.
"""
+ # Because of circular imports, we need to import this here.
+ from django.db.models.base import ObjectDoesNotExist
+
if not isinstance(data, (list, tuple)):
super(WhereNode, self).add(data, connector)
return
alias, col, field, lookup_type, value = data
- if field:
- params = field.get_db_prep_lookup(lookup_type, value)
- db_type = field.db_type()
- else:
- # This is possible when we add a comparison to NULL sometimes (we
- # don't really need to waste time looking up the associated field
- # object).
- params = Field().get_db_prep_lookup(lookup_type, value)
- db_type = None
+ try:
+ if field:
+ params = field.get_db_prep_lookup(lookup_type, value)
+ db_type = field.db_type()
+ else:
+ # This is possible when we add a comparison to NULL sometimes
+ # (we don't really need to waste time looking up the associated
+ # field object).
+ params = Field().get_db_prep_lookup(lookup_type, value)
+ db_type = None
+ except ObjectDoesNotExist:
+ # This can happen when trying to insert a reference to a null pk.
+ # We break out of the normal path and indicate there's nothing to
+ # match.
+ super(WhereNode, self).add(NothingNode(), connector)
+ return
if isinstance(value, datetime.datetime):
annotation = datetime.datetime
else:
@@ -190,3 +200,14 @@ class EverythingNode(object):
def relabel_aliases(self, change_map, node=None):
return
+
+class NothingNode(object):
+ """
+ A node that matches nothing.
+ """
+ def as_sql(self, qn=None):
+ raise EmptyResultSet
+
+ def relabel_aliases(self, change_map, node=None):
+ return
+