on_delete param where needed due to django 2 requirements

Author: jm2242

examples/starwars/models.py

@@ -5,23 +5,36 @@
 
 class Character(models.Model):
     name = models.CharField(max_length=50)
-    ship = models.ForeignKey('Ship', blank=True, null=True, related_name='characters')
+    ship = models.ForeignKey(
+        'Ship',
+        blank=True,
+        null=True,
+        on_delete=models.SET_NULL,
+        related_name='characters'
+    )
 
     def __str__(self):
         return self.name
 
 
 class Faction(models.Model):
     name = models.CharField(max_length=50)
-    hero = models.ForeignKey(Character)
+    hero = models.ForeignKey(
+        Character,
+        on_delete=models.SET_NULL,
+    )
 
     def __str__(self):
         return self.name
 
 
 class Ship(models.Model):
     name = models.CharField(max_length=50)
-    faction = models.ForeignKey(Faction, related_name='ships')
+    faction = models.ForeignKey(
+        Faction,
+        on_delete=models.SET_NULL,
+        related_name='ships'
+    )
 
     def __str__(self):
         return self.name

graphene_django/tests/models.py

@@ -15,7 +15,11 @@ class Pet(models.Model):
 
 class FilmDetails(models.Model):
     location = models.CharField(max_length=30)
-    film = models.OneToOneField('Film', related_name='details')
+    film = models.OneToOneField(
+        'Film',
+        on_delete=models.CASCADE,
+        related_name='details'
+    )
 
 
 class Film(models.Model):
@@ -37,8 +41,16 @@ def __str__(self):              # __unicode__ on Python 2
 class Article(models.Model):
     headline = models.CharField(max_length=100)
     pub_date = models.DateField()
-    reporter = models.ForeignKey(Reporter, related_name='articles')
-    editor = models.ForeignKey(Reporter, related_name='edited_articles_+')
+    reporter = models.ForeignKey(
+        Reporter,
+        on_delete=models.SET_NULL,
+        related_name='articles'
+    )
+    editor = models.ForeignKey(
+        Reporter,
+        on_delete=models.SET_NULL,
+        related_name='edited_articles_+'
+    )
     lang = models.CharField(max_length=2, help_text='Language', choices=[
         ('es', 'Spanish'),
         ('en', 'English')