Delete periodic job if job was deleted

esi/scraper/models.py

@@ -76,7 +76,7 @@ class Job(models.Model):
     query = models.CharField(max_length=255, default='', null=True, blank=True)
     spider = models.ForeignKey(Spider, default=None, null=True)
 
-    schedule_job = models.OneToOneField(PeriodicTask, on_delete=models.SET_NULL, blank=True, null=True, default=None)
+    schedule_job = models.OneToOneField(PeriodicTask, on_delete=models.CASCADE, blank=True, null=True, default=None)
     interval = models.CharField(max_length=7, choices=INTERVAL, default=None, null=True, blank=True)
     count = models.IntegerField(default=1, blank=True, null=True)
 
@@ -95,3 +95,7 @@ class Job(models.Model):
             'end_time': self.end_time,
             'status': self.status
         }
+
+    def delete(self, using=None, keep_parents=False):
+        self.schedule_job.delete()
+        super(Job, self).delete()