změna modelu on-delete

news/migrations/0004_auto_20201213_1410.py

@@ -0,0 +1,20 @@
+# Generated by Django 3.1.4 on 2020-12-13 13:10
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('wagtailimages', '0022_uploadedimage'),
+        ('news', '0003_auto_20201208_1922'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='news',
+            name='image',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='+', to='wagtailimages.image'),
+        ),
+    ]

news/models.py

@@ -18,7 +18,7 @@ class News(Page):
     date = models.DateField("Post date")
     body = RichTextField(blank=True)
     image = models.ForeignKey(
-        'wagtailimages.Image', null=True, on_delete=models.CASCADE, related_name='+'
+        'wagtailimages.Image', null=True, on_delete=models.SET_NULL, related_name='+'
     )
     
     search_fields = Page.search_fields + [