Oracle中管理用户（创建用户，用户加锁，用户解锁，修改用户密码，授权登录权限，撤销登录权限，授权连接权限，conn命令，创建角色，并为角色赋权限，将角色赋给指定用户）

SQL> create user abc identified by password;
用户已创建。
SQL> --为abc赋予登录权限，1. connect 2. create session
SQL> grant create session to abc;
授权成功。
SQL> --给用户加锁
SQL> alter user abc account lock;
用户已更改。
SQL> --给用户解锁
SQL> alter user abc account unlock;
用户已更改。
SQL> --修改密码
SQL> alter user abc identified by password;
用户已更改。
SQL> --admin option授权的级联
SQL> show user;
USER 为 "SYS"
SQL> --创建两个用户 jeff emi
SQL> create user jeff identified by password;
用户已创建。
SQL> create user emi identified by password;
用户已创建。
SQL> --授予登录的权限
SQL> grant create session to jeff with admin option;
授权成功。
SQL> --切换到jeff下
SQL> conn jeff/password
已连接。
SQL> show user
USER 为 "JEFF"
SQL> --jeff把create session赋予emi
SQL> grant create session to emi;
授权成功。
SQL> host cls
SQL> --回到管理员下
SQL> --撤销jeff登录的权限
SQL> revoke create session from jeff;
撤销成功。

SQL> show user;
USER 为 "JEFF"
SQL> conn / as sysdba
已连接。
SQL> grant connect,resource to jeff;
授权成功。
SQL> grant connect,resource to emi;
授权成功。
SQL> host cls
SQL> --切换到scott下，并且授予jeff查询emp的权限
SQL> conn scott/tiger
已连接。
SQL> grant select on emp to jeff with grant option;
授权成功。
SQL> --回到jeff下
SQL> conn jeff/password
已连接。
SQL> select ename from scott.emp;
ENAME                                                                          
----------                                                                     
SMITH                                                                          
ALLEN                                                                          
WARD                                                                           
JONES                                                                          
MARTIN                                                                         
BLAKE                                                                          
CLARK                                                                          
SCOTT                                                                          
KING                                                                           
TURNER                                                                         
ADAMS                                                                          
ENAME                                                                          
----------                                                                     
JAMES                                                                          
FORD                                                                           
MILLER                                                                         
已选择14行。
SQL> host cls
SQL> show user;
USER 为 "JEFF"
SQL> --jeff又把scott.emp的select授予emi
SQL> grant select on scott.emp to emi;
授权成功。
SQL> --切换到emi下
SQL> conn emi/password
已连接。

SQL> select ename from scott.emp;
ENAME                                                                          
----------                                                                     
SMITH                                                                          
ALLEN                                                                          
WARD                                                                           
JONES                                                                          
MARTIN                                                                         
BLAKE                                                                          
CLARK                                                                          
SCOTT                                                                          
KING                                                                           
TURNER                                                                         
ADAMS                                                                          
ENAME                                                                          
----------                                                                     
JAMES                                                                          
FORD                                                                           
MILLER                                                                         
已选择14行。
SQL> host cls
SQL> --回到scott下，并且撤销jeff查询emp表的权限
SQL> show user;
USER 为 "EMI"
SQL> conn scott/tiger
已连接。
SQL> revoke select on emp from jeff;
撤销成功。
SQL> conn jeff/passowrd
ERROR:
ORA-01017: invalid username/password; logon denied

警告: 您不再连接到 ORACLE。
SQL> exit

SQL> conn emi/password
已连接。

SQL> host cls
SQL> show user;
USER 为 "EMI"
SQL> conn sys/password
ERROR:
ORA-28009: connection as SYS should be as SYSDBA or SYSOPER

警告: 您不再连接到 ORACLE。
SQL> exit
SQL> /*
SQL>
SQL> 当创建完用户后，一般立即授予角色connect resource
SQL> */
SQL> --创建一个role
SQL> show user
USER 为 "SYS"

SQL> create role myrole1234;
角色已创建。
SQL> --为myrole1234授权, create session create table create view
SQL> grant create session,create table,create view to myrole1234;
授权成功。
SQL> --创建用户
SQL> create user my1234 identified by password;
用户已创建。
SQL> grant myrole1234 to my1234;
授权成功。
SQL> spool off