I'd suggest creating an HTML page that uses setIntreval() to repeatedly make AJAX calls to a PHP script that queries the your database. You could use JSON and PEAR to make the task a little easier.
Reference Links:
- http://www.w3schools.com/jsref/met_win_setinterval.asp
- http://api.jquery.com/category/ajax/
- http://api.jquery.com/jQuery.getJSON/
- http://php.net/manual/en/function.json-encode.php
- http://pear.php.net/manual/en/package.database.db-dataobject.php