title: How to use IS NOT NULL in Knex JS
body: <p>I am trying to create the following query using knex:</p>
  
  <p><code>SELECT * FROM users group by users.location having users.photo is not null</code> </p>
  
  <p>as follows:</p>
  
  <p><code>knex("users").groupBy("users.location").having("users.photo", "IS NOT", "Null")</code></p>
  
  <p>I am getting the following error on this:</p>
  
  <p><code>The operator IS NOT is not permitted</code></p>
  
  <p>I've gone through their documentation and couldn't find anything useful.</p>