The SQL file dbupdate-2.9-7-to-3.0-1.sql performs an upgrade from eZ publish 2.9-7 to 3.0-1.

In addition to importing the sql file to your database you should consider running the following scripts.
The scripts are run with
php -C scriptname

update/common/scripts/updatexmltext.php
- Fixes XML fields with inproper text encoding.
