报错现象:
SQL> alter user scott account unlock identified by tiger;
alter user scott account unlock identified by tiger
*
第 1 行出现错误:
ORA-01918: 用户 'SCOTT' 不存在
查询是否有SCOTT用户
SQL> select username from dba_users where username like 'SCOTT';
未选定行
创建SCOTT用户
SQL> create user scott identified by tiger;
create user scott identified by tiger