title: Using curly brackets({}) for REGEX in drupal db_query
body: <p>I have a where clause in my query like this "WHERE sth REGEXP '[0-9]{5,10}'"</p>
  
  <p>when I run this query in phpmyadmin it returns all matched records but in drupal it has no result.I think it's because drupal assumes everything like "{sth}" as a table.</p>
  
  <p>how can I solve this problem?</p>
  
  <p>Thanks</p>