title: django uuid or hashid field for primary keys? and how to prefix the generated ids with say "cust_"
body: <p>I am currently using <a href="https://pypi.org/project/django-shortuuidfield/" rel="nofollow noreferrer">django-shortuuidfield</a> to generate a unique UUID primary key on the <strong>Customer</strong> model as shown below</p>
  <pre class="lang-py prettyprint-override"><code>class Customer(models.Model):
      customer_id = ShortUUIDField()
      user = models.ForeignKey(User, on_delete=models.CASCADE)
      name = models.CharField(max_length=255, blank=False)
  </code></pre>
  <p>This guarantees that the <code>customer_id</code> field is unique with space and time. However, this generates an id similar to <code>B9fcKdMDHbwKCBoADjbNyA</code> and I want to prefix this with <code>cust_</code> to make it like this <code>cust_B9fcKdMDHbwKCBoADjbNyA</code>. How do I achieve this without making multiple db calls?</p>
  <p>I also looked into <a href="https://pypi.org/project/django-hashid-field/" rel="nofollow noreferrer">django-hashid-field</a> which supports prefixes out of the box but this does not guarantee UUID, and on a larger scale, we may run into unique contain failed issues that are not desirable.</p>
  <p>Any thoughts on this? Let me know...</p>