title: How to filter objects by ignoring upper and lower case letter django
body: <p>recently I started learning django and I have several questions. And one of them has relationship with __icontains. </p>
  
  <p><code>Company.objects.filter(name__icontains=receiver_company_name)</code></p>
  
  <p>And let's assume that I have one company which called for example Dota-2, and when I search in my db this company by typing "D", it's return for me Dota-2.
  And my question will be about, if my company "Dota-2" it's saved in db like this "Dota-2", and when I trying to search like this lowercase "d", it's return me empty array. How to make <strong>name_icontains</strong> search by ignoring lower and uppercase letter?</p>