un service a nécessairement un adhérent

services/migrations/0009_auto_20170211_1523.py

@@ -0,0 +1,28 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.5 on 2017-02-11 14:23
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+def remove_unaffected_services(apps, schema_editor):
+    db_alias = schema_editor.connection.alias
+    Service = apps.get_model('services', 'Service')
+    Service.objects.filter(adherent__isnull=True).delete()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('services', '0008_auto_20170211_0130'),
+    ]
+
+    operations = [
+        migrations.RunPython(remove_unaffected_services),
+        migrations.AlterField(
+            model_name='service',
+            name='adherent',
+            field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='services', to='adhesions.Adherent', verbose_name='Adhérent'),
+        ),
+    ]

services/models.py

@@ -49,7 +49,7 @@ class ServiceType(models.Model):
 
 
 class Service(models.Model):
-    adherent = models.ForeignKey(Adherent, verbose_name='Adhérent', null=True, blank=True, related_name='services')
+    adherent = models.ForeignKey(Adherent, verbose_name='Adhérent', related_name='services')
     service_type = models.ForeignKey(ServiceType, related_name='services',
                                      verbose_name='Type de service')
     label = models.CharField(blank=True, default='', max_length=128)