Improve duration handling for sessions and games

games/migrations/0012_alter_session_duration_calculated.py

@@ -0,0 +1,32 @@
+# Generated by Django 5.1.7 on 2025-03-25 20:30
+
+import django.db.models.expressions
+import django.db.models.functions.comparison
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("games", "0011_purchase_price_per_game"),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name="session",
+            name="duration_calculated",
+        ),
+        migrations.AddField(
+            model_name="session",
+            name="duration_calculated",
+            field=models.GeneratedField(
+                db_persist=True,
+                expression=django.db.models.functions.comparison.Coalesce(
+                    django.db.models.expressions.CombinedExpression(
+                        models.F("timestamp_end"), "-", models.F("timestamp_start")
+                    ),
+                    0,
+                ),
+                output_field=models.DurationField(),
+            ),
+        ),
+    ]