title: Tablename with ID "Some_ID" doesn't exist. Perhaps it was deleted? Django Sqlite
body: <p>I have database with many tables; three of those which are interlinked via primary and foreign keys are "Vendor_Details" , "Channel_Details" and "MSO_Details"</p>
  
  <p><strong>models.py</strong></p>
  
  <pre><code>class Vendor_Details(models.Model):
      class Meta:
          verbose_name_plural = "Vendor_Details"
      vendor_name = models.CharField(primary_key = True,max_length=50)
      mso_id = models.CharField(unique = True, max_length=20)
  
  class Channel_Details(models.Model):
      class Meta:
          verbose_name_plural = "Channel_Details"
      channel_id = models.CharField(primary_key = True, max_length=20)
      vendor_name = models.ForeignKey(Vendor_Details, on_delete=models.CASCADE)
      channel_logo = models.CharField(max_length=50)
      channel_name = models.CharField(max_length=50)
  
  class MSO_Details(models.Model):
      class Meta:
          verbose_name_plural = "MSO_Details"
      mso_id = models.ForeignKey(Vendor_Details, on_delete=models.CASCADE)
      channel_id = models.ForeignKey(Channel_Details, on_delete=models.CASCADE)
      channel_number = models.PositiveIntegerField()
  </code></pre>
  
  <p>So,
  Channel_Details is linked to Vendor_Details with vendor_name and
  MSO_Details is linked with Vendor_Details and Channel_Details with mso_id and channel_id respectively.</p>
  
  <p>Now, I am inside Django's Administrator's MSO_Details table and trying to click on edit icon of CHANNEL ID column i get a new window opens with message <code>Channel_ details with ID "CH6" doesn't exist. Perhaps it was deleted?</code> May be this is because channel_id is primary key of reference table and DB will not allow the changes? But then the message should had been something different. How can i handle this situation? I clicked on edit for CH_006 and message shows CH6. I am confused whats going on here, what is django's DB refering to here? 
  Note : I can very well add new CHANNEL_DETAILS after click add button.</p>