title: Checking database for NULL boolean value
body: <p>I have a field in a table that is boolean, a range of records have no value (not true or false). How do I write my SQL statement to find these?</p>
  
  <p>I have tried the following SQL statements without success:</p>
  
  <pre><code>1) SELECT * FROM table WHERE field = NULL
  2) SELECT * FROM table WHERE field != TRUE AND field != FALSE
  </code></pre>
  
  <p>Any help would be greatly appreciated.</p>
  
  <p>Many Thanks, Ben</p>