title: how to write a query to get find value in a json field in django
body: <p>I have a json field in my database which is like</p>
  
  <pre><code>jsonfield = {'username':'chingo','reputation':'5'}
  </code></pre>
  
  <p>how can i write a query so that i can find if a user name exists. something like</p>
  
  <pre><code>username = 'chingo'
  query = User.objects.get(jsonfield['username']=username)
  </code></pre>
  
  <p>I know the above query is a wrong but I wanted to know if there is a way to access it?</p>