If you can't use the automatic upgrade, you need to perform the following steps:
1. cd /usr/share/campsite/instance/database/upgrade/2.2.x (this may be in another location on your machine)
2. php -dinclude_path=/var/www/campsite/html:/usr/share/pear update_article_types.php
3. mysql -uroot -p[password]
4. use [database] (database will probably be 'campsite')
5. source tables.sql (there will be an error which you can ignore: ERROR 1064: You have an error in your SQL syntax near 'system php ./update_article_types.php)
5. source data-required.sql
This last script requires that you are running with MySQL 4.04 or later.