title: Django Models relation with primary key add extra "_id" to the column
body: <p>These are my two models, when I try to open City page on Django I get an error: "column city.country_id_id does not exist". I don't know why python adds extra <code>_id</code> there.</p>
  
  <pre><code>class Country(models.Model):
      country_id = models.CharField(primary_key=True,max_length=3)
      country_name = models.CharField(max_length=30, blank=True, null=True)
  
      class Meta:
          managed = False
          db_table = 'country'
  
  class City(models.Model):
      city_id=models.CharField(primary_key=True,max_length=3)
      city_name=models.CharField(max_length=30, blank=True, null=True)
      country_id = models.ForeignKey(Country, on_delete=models.CASCADE)
  
      class Meta:
          managed = False
          db_table = 'city'
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/Shj7x.png" alt="Image"></p>