title: how do I post a foreign key by some other field rather than primary key in django rest framework
body: <p>I am developing a pet management api and this is what I post to the body when assigning a day of the week to a pet :</p>
  <pre><code>{
     &quot;day&quot;: &quot;Sunday&quot;,
     &quot;pet_name&quot;: 2 &lt;-- how to add pet name (rather than the primary key)(this is a foreign key)
  }
  </code></pre>
  <p>How do I pass in the pet name which is the foreign key's field rather than the primary key field.</p>