Oracle如何进行用户密码修改和用户账号加锁、解锁？

a)用户修改密码：

select username,password from dba_users where username=’USER_NAME’;

alter user user_name identified by passwd_char;

conn user_name/passwd_char

b）用户账号锁定：

oracle用户账号加锁：alter user user_name account lock;

oracle用户账号解锁：alter user user_name account unlock;