summaryrefslogtreecommitdiff
path: root/django/db/models/sql
diff options
context:
space:
mode:
authorDavid Wobrock <david.wobrock@gmail.com>2021-09-29 00:00:50 +0200
committerMariusz Felisiak <felisiak.mariusz@gmail.com>2021-09-29 20:53:16 +0200
commitb2a0978610413e4cd5ebb716b8bfa7803dff8d5b (patch)
tree4ffaefa0f303e51266852bb8251eef28a5f8da54 /django/db/models/sql
parentaab76433ed585ebe997b94547e0d790605e01ad9 (diff)
[4.0.x] Fixed #33018 -- Fixed annotations with empty queryset.
Thanks Simon Charette for the review and implementation idea. Backport of dd1fa3a31b4680c0d3712e6ae122b878138580c7 from main
Diffstat (limited to 'django/db/models/sql')
-rw-r--r--django/db/models/sql/compiler.py8
-rw-r--r--django/db/models/sql/query.py1
2 files changed, 7 insertions, 2 deletions
diff --git a/django/db/models/sql/compiler.py b/django/db/models/sql/compiler.py
index 97288c83d7..d1009847e7 100644
--- a/django/db/models/sql/compiler.py
+++ b/django/db/models/sql/compiler.py
@@ -266,8 +266,12 @@ class SQLCompiler:
try:
sql, params = self.compile(col)
except EmptyResultSet:
- # Select a predicate that's always False.
- sql, params = '0', ()
+ empty_result_set_value = getattr(col, 'empty_result_set_value', NotImplemented)
+ if empty_result_set_value is NotImplemented:
+ # Select a predicate that's always False.
+ sql, params = '0', ()
+ else:
+ sql, params = self.compile(Value(empty_result_set_value))
else:
sql, params = col.select_format(self, sql, params)
ret.append((col, (sql, params), alias))
diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index d1c0c333f5..6436b25bae 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -143,6 +143,7 @@ class Query(BaseExpression):
"""A single SQL query."""
alias_prefix = 'T'
+ empty_result_set_value = None
subq_aliases = frozenset([alias_prefix])
compiler = 'SQLCompiler'