by yihui on WordPress.org
Converts the WordPress database (both tables and columns) to UTF-8 character set.
Admin interface
This plugin can convert your WordPress database (both tables and columns) to UTF-8 character set. It will be especially useful when you move your database from one server to another where the default CHARSET is not UTF-8.
Removes or replace international or special characters that can make your filenames not compliant with some servers or services.
Exports your standalone database SQL for import into a WP Multisite installation.
Execute arbitrary SQL queries against your WordPress database from the Admin.