User 'wj' attempts to perform a 'Select' command on the 'oats' database. Server looks towards the user table. Since the privileges granted within the user table are global, the request is successfully carried out. User 'wj' connection attempt successful. User 'wj' attempts to perform a 'Select' command on the 'oats' database.
Server looks towards the user table.
Server now looks towards the db table. If the privileges are in accordance with the user's request, access is granted. Otherwise, access is denied. User 'wj' connection via a given host is attempted. The MySQL server looks to the db table.