title: No matching object on query during save() override on model - DoesNotExist error thrown
body: <p>I'm overriding my Model save() to check and see if there is a Consumer (related object) that already exists with the email entered. When a Consumer does exist with a matching Email, the code executes as expected and associates the Case to the correct Consumer. However, if there is not an existing Consumer that exists with a matching Email, I'm receiving the error: "DoesNotExist: Consumer matching query does not exist."</p>
  
  <p>I've tried adjusting the save() method, however to me it looks correct (obviously, could be wrong here).</p>
  
  <p>Models.py </p>
  
  <pre><code>class Case(models.Model):
    ...
  
    def save(self,*args,**kwargs):
  
      if Consumer.objects.get(email__iexact=self.email):
          self.consumer = Consumer.objects.get(email__iexact=self.email)
  
      else:
          consumer = Consumer(first_name=self.first_name,last_name=self.last_name,email=self.email)
          consumer.save()
  
      return super().save(*args,**kwargs)
  </code></pre>
  
  <p>The expected results is to create a new Consumer object in the case that the Email entered on the Case does not match an already existing Consumer's email. Instead, it throws this error.</p>