Most WordPress webmasters use tools such as phpMyAdmin to make changes to their database. You can perform database operations through the command line too. SQL Executioner is also worth a look. It lets you execute queries against your database from the back-end.
This plugin doesn’t have an undo function, so you should know your SQL and be extremely careful what you execute. This plugin displays your list of tables, so you can put together your queries faster. SQL Executioner for WordPress is available as a free download.