学习目标：学习openGauss创建用户、修改用户属性、更改用户权限和删除用户
部分学习内容如下：
课后作业：
1.创建用户user1、user2和user3，user1具有CREATEROLE权限，user2具有CREATEDB权限，要求使用两种不同的方法设置密码
omm=# create user user1 createrole identified by 'password_1';
NOTICE: The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# create user user2 createdb password 'password_2';
NOTICE: The encrypted password contains MD5 ciphertext, which is not secure.
omm=# CREATE ROLE
create user user3 password 'password_3';
NOTICE: The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
2.修改用户user1的密码
omm=# alter user user1 identified by 'password_4' replace 'password_1';
NOTICE: The encrypted password contains MD5 ciphertext, which is not secure.
ALTER ROLE
omm=# \du+
List of roles
Role name | Attributes
| Member of | Description
-----------+------------------------------------------------------------------------------------------------------------------
+-----------+-------------
gaussdb | Sysadmin
| {} |
omm | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin, UseFT
| {} |
user1 | Create role
| {} |
user2 | Create DB
| {} |
user3 |
| {} |
3.重命名用户user2
omm=# alter user user2 rename to user4;
NOTICE: MD5 password cleared because of role rename
ALTER ROLE
omm=# \du
List of roles
Role name | Attributes
| Member of
-----------+------------------------------------------------------------------------------------------------------------------
+-----------
gaussdb | Sysadmin
| {}
omm | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin, UseFT
| {}
user1 | Create role
| {}
user3 |
| {}
user4 | Create DB
| {}
4.将用户user1的权限授权给用户user3，再回收用户user3的权限
omm=# grant user1 to user3;
GRANT ROLE
omm=# \du
List of roles
Role name | Attributes
| Member of
-----------+------------------------------------------------------------------------------------------------------------------
+-----------
gaussdb | Sysadmin
| {}
omm | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin, UseFT
| {}
user1 | Create role
| {}
user3 |
| {user1}
user4 | Create DB
| {}
omm=# revoke all privilege from user3;
ALTER ROLE
omm=# \du
List of roles
Role name | Attributes
| Member of
-----------+------------------------------------------------------------------------------------------------------------------
+-----------
gaussdb | Sysadmin
| {}
omm | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin, UseFT
| {}
user3 |
| {user1}
user4 | Create DB
| {}
user1 | Create role
| {}
5.删除所有创建用户
omm=# drop user user1;
DROP ROLE
omm=# drop user user3;
DROP ROLE
omm=# drop user user4;
DROP ROLE
omm=# \du
gaussdb | Sysadmin
| {}
omm | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin, UseFT
| {}
List of roles
Role name | Attributes
| Member of
-----------+------------------------------------------------------------------------------------------------------------------
+-----------
过程中使用\du或\du+查看用户信息
