title: Django database - how to add this column in raw SQL
body: <p>Suppose I have my models set up already.</p>
  
  <pre><code>class books(models.Model):
      title = models.CharField...
      ISBN = models.Integer...
  </code></pre>
  
  <p>What if I want to add this column to my table?</p>
  
  <pre><code>user = models.ForeignKey(User, unique=True)
  </code></pre>
  
  <p>How would I write the raw SQL in my database so that this column works?</p>