I recently ran into an issue where I wasn't the admin in a Wordpress install, and after running this bit of SQL, I was quickly back in command:
INSERT INTO `wp_users` (`user_login`, `user_pass`, `user_nicename`, `user_email`, `user_status`)
VALUES ('ryo', MD5('easy123'), 'firstname lastname', '[email protected]', '0');
INSERT INTO `wp_usermeta` (`umeta_id`, `user_id`, `meta_key`, `meta_value`)
VALUES (NULL, (Select max(id) FROM wp_users), 'wp_capabilities', 'a:1:{s:13:"administrator";s:1:"1";}');
INSERT INTO `wp_usermeta` (`umeta_id`, `user_id`, `meta_key`, `meta_value`)
VALUES (NULL, (Select max(id) FROM wp_users), 'wp_user_level', '10');
Hope that helps, Ryo
References