CREAT USER exercise IDENTIFIED BY 123456
DEFAULT TABLESPACE mldn_data
TEMPORARY mldn_temp
QUOTA 1M ON mldn_data 创建用户
QUOTA 2M ON users
ACCONT UNLOCK
PASSWORD EXPIRE;
DROP USER exercise; 删除用户
GRANT CREATE SESSION TO exercise WITH ADMINOPTION; 为用户授权,使用“WITH ADMIN OPTION”，表示该用户可以将这些权限继续授予别的用户
CREAT ROLE LICONGCONG; 创建角色
CREAT ROLE LICONGCONG; 删除角色
CREAT ROLE LICONGCONG IDENTIFIED BY456789; 创建带有密码的角色
SELECT * FROM DBA_ROLES; 查看角色字典
GRANT CREATE SESSION,CREATE TABLE,CREATEVIEW TO LICONGCONG;为角色授权
SELECT * FROM ROLE_SYS_PRIVS
WHERE ROLE IN (LICONGCONG) 查看角色权限
ORDER BY ROLE;
GRANT LICONGCONG TO exercise; 为用户授予角色
PRIVILEGE; 查看该用户通过角色被授予的权限（SQLPLUS）登录
ALTER ROLE LICONGCONG IDENTIFIED BY123456; 修改角色密码
ALTER ROLE LICONGCONG NOT IDENTIFIED; 取消角色密码
REVOKE CREATE SESSION FROM LICONGCONG; 收回角色权限
SELECT *
FROM ROLE_SYS_PRIVS
WHERE ROLE IN('CONNECT','RESOURCE') 查看'CONNECT'和'RESOURCE'的权限，这两个角色拥有经常用到的权限
ORDER BY ROLE;