title: Delete Fields Where a Null Value Appeard
body: <p><img src="https://i.stack.imgur.com/VaGb1.png" alt="blank"></p>
  
  <p>So, how do i delete this? I acidentially wrote about 1,500 blank records with prefix null and code = 0</p>
  
  <p>I tried this query and it does nothing:</p>
  
  <pre><code>DELETE FROM Course where prefix IS NULL and code = 0;
  </code></pre>
  
  <p>The feedback I get is 0 results were deleted.</p>
  
  <p>Anyone?</p>