创建用户

CREATE USER ch IDENTIFIED BY '123456';

授权

• 所有权限

GRANT ALL PRIVILEGES ON *.* TO 'ch'@'%' IDENTIFIED BY '123456';

给ch用户所有数据库权限，“%”的意思是允许所有机器远程连接该库

注意：GRANT ALL PRIVILEGES ON . TO 'ch'@'%' （这样是报错的）
ERROR 1133 (42000): Can't find any matching row in the user table

• 指定权限

GRANT SELECT, UPDATE, INSERT, DELETE ON test.* TO 'ch'@'192.168.1.168' IDENTIFIED BY '123456';

给ch用户test库的 CRUD 权限，并且只有 '192.168.1.168' 机器可以远程连接该库

运行 flush privileges

mysql> flush privileges;                                                                
Query OK, 0 rows affected (0.00 sec)

让修改生效