When I Got my server,even I had the same problem accessing the mysql from MySQL client application,
Then I granted the Mysql permission, with following query.
it worked Great
**GRANT ALL PRIVILEGES ON db_base.* TO db_user @'%' IDENTIFIED BY 'db_passwd';**
db_base is the database Name
db_user is database User
db_passwd is the database password
Once you execute this flush it, by the following command
FLUSH PRIVILEGES;
Suppose if you are looking to give privileges to access certain tables in the Database you can use the following command
GRANT ALL PRIVILEGES ON db_base.HELLOWORLD TO db_user @'%' IDENTIFIED BY 'db_passwd';
Where HELLOWORLD
is the table Name