From 25d06247390bab80c4183a39453672d53f20ab4f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20N?= <Chr0nos@users.noreply.github.com>
Date: Thu, 10 Oct 2024 12:05:10 +0200
Subject: [PATCH] Annotated count fix index error (#1707)

* Fix for annotated count

* updated changelog

* added tests to show what the fix is about
---
 CHANGELOG.rst             | 3 +++
 tests/test_aggregation.py | 7 +++++++
 tortoise/queryset.py      | 2 ++
 3 files changed, 12 insertions(+)

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 04c6d693e..e5e4b06c0 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -8,6 +8,9 @@ Changelog
 
 0.21
 ====
+0.21.7
+------
+- Fix bug when using annotate and count at the same time but the annotation does not match anything, leading to an IndexError
 
 0.21.6
 ------
diff --git a/tests/test_aggregation.py b/tests/test_aggregation.py
index 93b2fbcc6..c4c932898 100644
--- a/tests/test_aggregation.py
+++ b/tests/test_aggregation.py
@@ -236,3 +236,10 @@ async def test_count_after_aggregate_m2m(self):
 
         res = await query.count()
         assert res == 2
+
+    async def test_count_without_matching(self) -> None:
+        await Tournament.create(name="Test")
+
+        query = Tournament.annotate(events_count=Count("events")).filter(events_count__gt=0).count()
+        result = await query
+        assert result == 0
diff --git a/tortoise/queryset.py b/tortoise/queryset.py
index ae3ce5079..6e0e7897f 100644
--- a/tortoise/queryset.py
+++ b/tortoise/queryset.py
@@ -1335,6 +1335,8 @@ def __await__(self) -> Generator[Any, None, int]:
 
     async def _execute(self) -> int:
         _, result = await self._db.execute_query(str(self.query))
+        if not result:
+            return 0
         count = list(dict(result[0]).values())[0] - self.offset
         if self.limit and count > self.limit:
             return self.limit