Don't cascade user deletion into deletion of exams etc

website/education/migrations/0010_auto_20190130_2048.py

+# Generated by Django 2.1.5 on 2019-01-30 19:48
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('education', '0009_auto_20181219_2104'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='exam',
+            name='uploader',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, to='members.Member', verbose_name='uploader'),
+        ),
+        migrations.AlterField(
+            model_name='summary',
+            name='uploader',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, to='members.Member', verbose_name='uploader'),
+        ),
+    ]

website/education/models.py

@@ -111,7 +111,8 @@ class Exam(models.Model, metaclass=ModelTranslateMeta):
     uploader = models.ForeignKey(
         Member,
         verbose_name=_('uploader'),
-        on_delete=models.CASCADE,
+        on_delete=models.SET_NULL,
+        null=True,
     )
 
     uploader_date = models.DateField(
@@ -181,7 +182,8 @@ class Summary(models.Model, metaclass=ModelTranslateMeta):
     uploader = models.ForeignKey(
         Member,
         verbose_name=_('uploader'),
-        on_delete=models.CASCADE,
+        on_delete=models.SET_NULL,
+        null=True,
     )
 
     uploader_date = models.DateField(