From 0e464ed3e6b77bbbd6069c27924c624c3fe7c0d0 Mon Sep 17 00:00:00 2001
From: Dan Collins <dcollinsn@gmail.com>
Date: Mon, 5 Feb 2018 16:53:00 -0500
Subject: [PATCH] Django 2.0: Add on_delete to ForeignKeys

---
 async/migrations/0001_initial.py |  6 +++---
 async/models.py                  | 16 +++++++++++-----
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/async/migrations/0001_initial.py b/async/migrations/0001_initial.py
index 915b9db..20b1b12 100644
--- a/async/migrations/0001_initial.py
+++ b/async/migrations/0001_initial.py
@@ -50,7 +50,7 @@ class Migration(migrations.Migration):
                 ('started', models.DateTimeField(null=True, blank=True)),
                 ('executed', models.DateTimeField(null=True, blank=True)),
                 ('cancelled', models.DateTimeField(null=True, blank=True)),
-                ('group', models.ForeignKey(related_name='jobs', blank=True, to='async.Group', null=True)),
+                ('group', models.ForeignKey(related_name='jobs', blank=True, to='async.Group', null=True, on_delete=models.SET_NULL)),
             ],
             options={
             },
@@ -59,13 +59,13 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='group',
             name='final',
-            field=models.ForeignKey(related_name='ends', blank=True, to='async.Job', null=True),
+            field=models.ForeignKey(related_name='ends', blank=True, to='async.Job', null=True, on_delete=models.SET_NULL),
             preserve_default=True,
         ),
         migrations.AddField(
             model_name='error',
             name='job',
-            field=models.ForeignKey(related_name='errors', to='async.Job'),
+            field=models.ForeignKey(related_name='errors', to='async.Job', on_delete=models.CASCADE),
             preserve_default=True,
         ),
     ]
diff --git a/async/models.py b/async/models.py
index 98c2aa4..92442b7 100644
--- a/async/models.py
+++ b/async/models.py
@@ -35,8 +35,10 @@ class Group(models.Model):
     reference = models.CharField(max_length=100)
     description = models.TextField(blank=True, null=True)
     created = models.DateTimeField(auto_now_add=True)
-    final = models.ForeignKey('Job', blank=True, null=True,
-        related_name='ends')
+    final = models.ForeignKey('Job',
+                              on_delete=models.SET_NULL,
+                              blank=True, null=True,
+                              related_name='ends')
 
     def __unicode__(self):
         return u'%s' % self.reference
@@ -156,8 +158,10 @@ class Job(models.Model):
     executed = models.DateTimeField(null=True, blank=True)
     cancelled = models.DateTimeField(null=True, blank=True)
 
-    group = models.ForeignKey(Group, related_name='jobs',
-        null=True, blank=True)
+    group = models.ForeignKey(Group,
+                              on_delete=models.SET_NULL,
+                              related_name='jobs',
+                              null=True, blank=True)
 
     def __unicode__(self):
         # __unicode__: Instance of 'bool' has no 'items' member
@@ -246,7 +250,9 @@ class Error(models.Model):
     """
         Recorded when an error happens during execution of a job.
     """
-    job = models.ForeignKey(Job, related_name='errors')
+    job = models.ForeignKey(Job,
+                            on_delete=models.CASCADE,
+                            related_name='errors')
     executed = models.DateTimeField(auto_now_add=True)
     exception = models.TextField()
     traceback = models.TextField()