The Kartris database is protected from casual deletion or modification of data by a series of triggers. The various stored procedures that update data disable a trigger, update the data, and then re-enable it again.
If you try to execute SQL directly to modify data, you will find it will fail. Similarly, if you open up the database tables directly in SQL Server Management Studio and try to change, add or delete data, you will get a similar trigger error - no update will occur.
If you need to modify data outside of the Kartris admin area, you can disable the triggers temporarily on a single table, or on all tables.
Go to Coniguration > Database Admin and then select the 'Triggers' tab. Typically triggers will be reactivated when queries on those tables next fire up, or you can reactivate them manually from this page too.
If you need to modify data and your site admin area is offline, so you cannot turn the triggers off from there, you can run the stored procedures from SQL Management Studio directly: