以特权身份进行链接数据库
sqlplus / as sysdba
查看账号状态
SELECT username, account_status FROM dba_users where username = ‘xxx'
将用户解锁
ALTER USER xxxx ACCOUNT UNLOCK;
作废原来的password
ALTER USER xxxx PASSWORD EXPIRE;
将账号有效期设置为永久
ALTER PROFILE default LIMIT PASSWORD_LIFE_TIME UNLIMITED;
更改用户密码
ALTER USER 用户名 IDENTIFIED BY 密码;