title: questions about mysql_real_escape_string
body: <p>I'm developing my personal web site using php. everything is ok but I just read <code>mysql_real_escape_string</code> manual in <a href="http://www.php.net/manual/en/%E2%80%8Bfunction.mysql-real-escape-string.php" rel="nofollow noreferrer">php.net</a> and found two things:</p>
  <blockquote>
  <ol>
  <li>This function must always (<strong>with few exceptions</strong>) be used to make data safe before sending a query to MySQL.</li>
  <li>mysql_real_escape_string() <strong>does not escape % and _</strong>. These are wildcards in MySQL if combined with LIKE, GRANT, or REVOKE.</li>
  </ol>
  </blockquote>
  <p>I have two questions:<br />
  1-what are these exceptions?<br />
  2- how to escape those characters?<br /></p>