I almost (that means VERY!) sure that you have not ROOT privileges to a mysql database at an ISP, since that would give you )and everybody else with an account there) total control of the complete MySQL system !
At most you will have some “admin” privileges (after configuring an admin-user with the tool the the ISP offers – most probably phpMyAdmin)
Most often you must log on with “user_admin” or “mydomain_admin” or something like that … That would – with an appropiate webserver/mysql-configuration – give you full access to the databases that are yours and no other!