Roles in MYSQL (1 reply)

Hi all

In mySql, as far as my understanding goes, its possible for us to grant privileges for same user name from different hosts. eg. user 'karthick' @ localhost could be assigned privileges different from user 'karthick' @ madhost.com

But, will it be possible to connect to a database with same user name and from same host but with different privileges? For eg. like fopen("file.txt","r") & fopen("file.txt","w"); will we be able to connect to database from the same host with the same username but different privileges?

http://dev.mysql.com/doc/workbench/en/wb-adding-roles.html says that roles can be added but I am not able to find how it can be done programmatically and also as how to set and unset a role for a connection.