超级数据库管理员：
   GRANT ALL PRIVILEGES ON *.* TO 'superadmin'@'localhost' IDENTIFIED BY PASSWORD 'superadminpwd' WITH GRANT OPTION;
   GRANT ALL PRIVILEGES ON *.* TO 'superadmin'@'127.0.0.1' IDENTIFIED BY PASSWORD 'superadminpwd' WITH GRANT OPTION;

清理不安全因素
  删除空密码，空用户，空IP地址的账号
  delete from mysql.user where `Host`='' or `User`='' or `Password`='';

  删除root账号，删除test测试数据库
  delete from mysql.user where`User`='root';
  删除test测试数据库.如果需要，可以建立指定的非业务库
  drop database test;
    
备份帐户: 官方文档: http://dev.mysql.com/doc/refman/5.5/en/mysqldump.html
   grant SELECT,SHOW VIEW, TRIGGER, LOCK TABLES ON *.* TO 'dump'@'localhost' identified by 'dumppwd';

复制用户:不仅是复制，部分工具需要REPLICATION CLIENT, SELECT权限
   GRANT REPLICATION SLAVE, REPLICATION CLIENT, SELECT ON *.* TO 'repl'@'192.168.%' IDENTIFIED BY PASSWORD 'replpwd';

应用程序用户:
   GRANT UPDATE,DELETE,SELECT,INSERT, CREATE TEMPORARY TABLES ON db_program.* TO'dev'@'192.168.%' IDENTIFIED BY PASSWORD 'devpwd';

DBA:
   GRANT CREATE, DROP, LOCK TABLES, EVENT, ALTER, INDEX, TRIGGER, CREATE VIEW, ALTER ROUTINE, CREATE ROUTINE, EXECUTE, FILE, UPDATE,DELETE,SELECT,INSERT, CREATE TEMPORARY TABLES  ON *.* TO'dba'@'192.168.%' IDENTIFIED BY PASSWORD 'dbapwd';