mark Favourite to be deleted when related user is deleted

favourite does not seem like a model that needs to be kept around after user deletion

plotsearch/migrations/0038_alter_favourite_user.py

@@ -0,0 +1,25 @@
+# Generated by Django 4.2.16 on 2024-11-20 11:55
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ("plotsearch", "0037_alter_areasearchattachment_options_and_more"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="favourite",
+            name="user",
+            field=models.ForeignKey(
+                null=True,
+                on_delete=django.db.models.deletion.CASCADE,
+                to=settings.AUTH_USER_MODEL,
+            ),
+        ),
+    ]

plotsearch/models/plot_search.py

@@ -423,7 +423,7 @@ class MeetingMemo(models.Model):
 
 
 class Favourite(models.Model):
-    user = models.ForeignKey(User, null=True, on_delete=models.SET_NULL)
+    user = models.ForeignKey(User, null=True, on_delete=models.CASCADE)
 
     created_at = models.DateTimeField(auto_now_add=True, db_index=True)
     modified_at = models.DateTimeField(auto_now=True)