On Linux Plesk running server if  you want to access all the DB’s from remote mysql client, please follow these instructions.

To assign the full privileges to admin user on all the databases on server running plesk

1. To go to mysql prompt use command

# mysql -uadmin -p`cat /etc/psa/.psa.shadow`

2. To assign the admin user on all the databases on server running plesk

mysql > GRANT ALL ON *.* TO admin@’192.168.1.2′ IDENTIFIED BY ‘yourpassword’;

Where,
*.           => For all the databases on the server
admin  => User Name to be used with full privileges
192.168.1.2 => The Ip address of the machine from which you wish to access all the db’s ( Remote Host )

 To verify The connectivity of the DB from remote host run the following command

mysql -h 192.168.1.1 -u admin -pyourpassword

Where,
192.168.1.1 => Is the mysql server IP Address