Ensure Report.updated_at is the greatest between the current value and the last history.

Author: epou

tigaserver_app/migrations/0044_auto_20240124_1533.py

@@ -6,7 +6,6 @@
 import django.contrib.gis.db.models.fields
 from django.db import migrations, models, transaction
 from django.db.models import OuterRef, Subquery
-from django.db.models.functions import Greatest
 from django.db.utils import IntegrityError
 import django.db.models.deletion
 
@@ -222,24 +221,6 @@ def populate_report_history_table(apps, schema_editor):
 
     return
 
-    # NOTE: this gets blocked...
-    print("Updating Report.updated_at with last modification date (if necessary)")
-    Report.objects.annotate(
-        last_update=Greatest(
-            models.F('updated_at'),
-            Subquery(
-                HistoricalReport.objects.filter(
-                    **{Report._meta.pk.name: OuterRef('pk')}
-                ).order_by().annotate(
-                    # NOTE: Using models.Func to avoid adding GROUP BY
-                    # See: https://stackoverflow.com/questions/42543978/django-1-11-annotating-a-subquery-aggregate/69020732#69020732
-                    last_history_date=models.Func(models.F('history_date'), function='MAX')
-                ).values('last_history_date')
-            )
-        )
-    ).update(updated_at=models.F('last_update'))
-
-
 
 class Migration(migrations.Migration):
 

tigaserver_app/migrations/0045_auto_20240124_1543.py

@@ -2,6 +2,24 @@
 
 from django.db import migrations, models
 
+from django.db.models import OuterRef, Subquery
+from django.db.models.functions import Greatest
+
+def update_report_updated_at_field(apps, schema_editor):
+    HistoricalReport = apps.get_model("tigaserver_app", "HistoricalReport")
+    Report = apps.get_model("tigaserver_app", "Report")
+
+    print("Updating Report.updated_at with last modification date (if necessary)")
+    Report.objects.annotate(
+        last_update=Greatest(
+            models.F('updated_at'),
+            Subquery(
+                HistoricalReport.objects.filter(
+                    **{Report._meta.pk.name: OuterRef('pk')}
+                ).order_by('-history_date').values('history_date')[:1]
+            )
+        )
+    ).update(updated_at=models.F('last_update'))
 
 class Migration(migrations.Migration):
 
@@ -10,6 +28,7 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
+        migrations.RunPython(update_report_updated_at_field, migrations.RunPython.noop),
         migrations.AddConstraint(
             model_name='report',
             constraint=models.CheckConstraint(check=models.Q(models.Q(('deleted_at__isnull', True), ('version_number', 0)), models.Q(('deleted_at__isnull', False), ('version_number', -1)), _connector='OR'), name='version_number_constraint'),