Clearing Drupal's cache
This snippet clears out Drupal's cache.
You may need to do this after moving your site from one host to another, for example. Also useful when you install new modules or generally troubleshoot things. It is relatively harmless. Your site might slow down a bit afterwards while the cache fills back up. You will never lose irretrievable data with this query. Use it as needed.
DELETE FROM cache;
So the complete
So the complete PHP-statement would be:
<?phpdb_query("DELETE FROM {cache};");
?>