更改当前数据库的编码
ALTER DATABASE `koubei` DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci
ALTER TABLE `category` DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci

#增加root用户管理权限.
REVOKE ALL PRIVILEGES ON * . * FROM root@%;

GRANT ALL PRIVILEGES ON * . * TO root@% WITH GRANT OPTION MAX_QUERIES_PER_HOUR 0 MAX_CONNECTIONS_PER_HOUR 0 MAX_UPDATES_PER_HOUR 0 MAX_USER_CONNECTIONS 0 ;