title: Performing a mysql_real_escape_string on checkboxes, radio buttons or drop-down menus?
body: <p>Is there any way someone can do a sql injection for checkboxes, radio buttons or drop-down menus (ex. country, year of birth)?</p>
  
  <p>Also, hypothetically, if someone enters their cat's name into a text field, would it be enough to run the following line of code before I insert them into the mysql table?</p>
  
  <pre><code>$catsName = preg_replace('/[^a-z]/i', '', $_POST['yourCat']);
  </code></pre>
  
  <p>Or would I have to this in addition?</p>
  
  <pre><code>$catsName = mysql_real_escape_string($_POST['yourCat']);
  </code></pre>