title: How to compare against fields that are `null` (empty)?
body: <p>I have a table in a CakePHP 3 application called <code>downloads</code> which has a column called <code>master</code>. The field type is set to <code>TINYINT(1)</code></p>
  
  <p>I can find any records where <code>downloads.master == 1</code> like this:</p>
  
  <pre><code>$query = $this-&gt;Downloads-&gt;find()-&gt;where(['master' =&gt; true]);
  </code></pre>
  
  <p>But Cake won't let me query for ones where <code>downloads.master !== 1</code>. None of these work, and all return an empty array/object when the query is executed:</p>
  
  <pre><code>$query = $this-&gt;Downloads-&gt;find()-&gt;where(['master' =&gt; false]);
  $query = $this-&gt;Downloads-&gt;find()-&gt;where(['master' =&gt; 0]);
  $query = $this-&gt;Downloads-&gt;find()-&gt;where(['master' =&gt; null]);
  $query = $this-&gt;Downloads-&gt;find()-&gt;where(['master' =&gt; '']);
  </code></pre>
  
  <p>What do you use as the condition to make this possible? My thinking was that it should be <code>false</code> since that's the opposite to <code>true</code>, but as with most things in CakePHP 3 they like to make it more complicated than necessary...</p>
  
  <p>I've examined the records in my table using phpMyAdmin and there are indeed both records where <code>master == 1</code> and <code>master == null</code> so it's not a case of there's zero results to return.</p>