title: Conditional update in SQLite
body: <p>Can I create in <code>SQLite</code> a statement like this?</p>
  
  <pre><code>update books set
  (if number_of_pages &gt; 0 then number_of_pages = number_of_pages - 1)
  where book_id = 10
  </code></pre>
  
  <p>Is there a working syntax for this?</p>