Merge 616eb3b into b63ddd6

docs/changelog.rst

@@ -5,7 +5,7 @@ Changelog
 ------------------
 
 - Nothing changed yet.
-
+- Remove unnecessary COUNT queries to speed up export
 
 3.3.4 (2023-12-09)
 ------------------

import_export/admin.py

@@ -1,5 +1,6 @@
 import logging
 import warnings
+from contextlib import contextmanager
 
 import django
 from django import forms
@@ -69,6 +70,24 @@ def changelist_view(self, request, extra_context=None):
         return super().changelist_view(request, extra_context)
 
 
+class FakePaginator:
+    count = 0
+
+
+def _get_paginator(request, queryset, per_page):
+    return FakePaginator()
+
+
+@contextmanager
+def temp_attr(obj, attr_name, new_value):
+    original_value = getattr(obj, attr_name)
+    setattr(obj, attr_name, new_value)
+    try:
+        yield
+    finally:
+        setattr(obj, attr_name, original_value)
+
+
 class ImportMixin(BaseImportMixin, ImportExportMixinBase):
     """
     Import mixin.
@@ -741,7 +760,12 @@ def get_export_queryset(self, request):
         changelist_kwargs["sortable_by"] = self.sortable_by
         if django.VERSION >= (4, 0):
             changelist_kwargs["search_help_text"] = self.search_help_text
-        cl = ChangeList(**changelist_kwargs)
+
+        # Temporarily set to False to avoid unnecessary COUNT queries.
+        with temp_attr(self, "show_full_result_count", False):
+            # Temporarily set to FakePaginator to avoid unnecessary COUNT queries.
+            with temp_attr(self, "get_paginator", _get_paginator):
+                cl = ChangeList(**changelist_kwargs)
 
         return cl.get_queryset(request)
 

tests/core/tests/test_admin_integration.py

@@ -680,7 +680,8 @@ def test_export(self):
             "file_format": "0",
         }
         date_str = datetime.now().strftime("%Y-%m-%d")
-        response = self.client.post("/admin/core/book/export/", data)
+        with self.assertNumQueries(7):  # Should not contain COUNT queries from ModelAdmin.get_results()
+            response = self.client.post("/admin/core/book/export/", data)
         self.assertEqual(response.status_code, 200)
         self.assertTrue(response.has_header("Content-Disposition"))
         self.assertEqual(response["Content-Type"], "text/csv")