密碼管理 1、執行create命令創建用戶，密碼： `create user 'test5'@'localhost' identified by '123456' ` 2、修改用戶密碼的方式： (1) `mysql > alter user 'test5'@'localhost' identified by '1234567';` (2) `mysql > set password for 'test5'@'localhost'=PASSWORD('12345678');` (3) shell > mysqladmin -u 用戶名 -p舊密碼 password 新密碼 　 shell > mysqladmin -u root -h host_name password "new_password" ##沒有設置過密碼可用這條命令 3、修改本身用戶密碼： ~~~ mysql > alter user user() identified by '1234567'; mysql > set password = password('1234567'); ~~~ 4、設置密碼過期策略 （1）、default_password_lifetime=180 設置180天過期（在my.cnf中定義) default_password_lifetime=0 設置密碼不過期 （2）、如果為每個用戶設置密碼過期策略，則會覆蓋上述系統參數 ~~~ `alter user 'test'@'localhost' password expire interval 90 day;` alter user 'test'@'localhost' password expire never; ##密碼不過期 alter user 'test'@'localhost' password expire default;###默認過期策略，永不過期 ~~~ （3)、手動強制某個用戶密碼過期 `alter user 'test'@'localhost' password expire;` ~~~ 示例： mysql> alter user 'root'@'localhost' password expire; Query OK, 0 rows affected (0.00 sec) 告警信息： mysql> select 1; ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement. mysql> alter user user() identified by '123456'; ###重置密碼 ~~~