 <p>You seem to store empty string (<code>''</code>) rather than <code>NULL</code> in the empty fields. Those are different things in <code>MySQL</code>.</p> <p>Use this:</p> <pre><code>SELECT * FROM cities WHERE cssstyle &gt; '' </code></pre> <p>By using "greater than" you give <code>MySQL</code> posibility to use an index range scan on <code>cssstyle</code></p>