openGuass每日一练第19天|学习心得体会

原创小严 2022-12-12

307

课程学习内容

软件版本 ：openGauss 3.0.0

掌握openGauss用户和角色管理。

使用create user创建的用户与使用create role创建的用户的区别在于，前者可以直接连接登录数据库，而使用create role创建的用户不能直接登录到数据库。必须添加LOGIN权限后，才能登录到数据库管理系统。
删除用户，首先需要将用户拥有的数据库对象转移或者删除。

数据库实操内容

环境准备

gsql -r

CREATE TABLESPACE test_tbs RELATIVE LOCATION ‘tablespace/test_tbs1’;

CREATE DATABASE testdb WITH TABLESPACE = test_tbs;

root@modb:~# su - omm
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# CREATE TABLESPACE test_tbs RELATIVE LOCATION 'tablespace/test_tbs1';
CREATE TABLESPACE
omm=# CREATE DATABASE testdb WITH TABLESPACE = test_tbs;
CREATE DATABASE

使用create user创建用户

使用create user创建的用户，具有登录权限。

–创建一个名叫user1的数据库用户，其密码为kunpeng@1234，并将数据库testdb所有的权限都授予用户user1：

CREATE USER user1 IDENTIFIED BY ‘kunpeng@1234’;

GRANT ALL ON DATABASE testdb TO user1;

omm=#  CREATE USER user1 IDENTIFIED BY 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=#  GRANT ALL ON DATABASE testdb TO user1;
GRANT
omm=#

–执行下面的gsql元命令，查看系统目前有哪些数据库：

\l

omm=# \l
                         List of databases
   Name    | Owner | Encoding | Collate | Ctype | Access privileges 
-----------+-------+----------+---------+-------+-------------------
 omm       | omm   | UTF8     | C       | C     | 
 postgres  | omm   | UTF8     | C       | C     | 
 template0 | omm   | UTF8     | C       | C     | =c/omm           +
           |       |          |         |       | omm=CTc/omm
 template1 | omm   | UTF8     | C       | C     | =c/omm           +
           |       |          |         |       | omm=CTc/omm
 testdb    | omm   | UTF8     | C       | C     | =Tc/omm          +
           |       |          |         |       | omm=CTc/omm      +
           |       |          |         |       | user1=CTc/omm    +
           |       |          |         |       | user1=APm/omm
(5 rows)

omm=#

–执行下面的gsql元命令，查看系统目前有哪些用户：

\du

\q

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     |                                                                                              
                    | {}

omm=# \q
omm@modb:~$

–用刚刚创建的数据库用户user1登录到数据库testdb

gsql -d testdb -U user1 -W kunpeng@1234 -r

\q

omm@modb:~$ gsql -d testdb   -U user1   -W kunpeng@1234 -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

testdb=> \q
omm@modb:~$

使用create role创建用户

使用create role命令创建的用户user2，没有登录权限。

–创建一个新的名叫user2的角色，并将数据库testdb所有的权限都授予用户user2：用户user2对数据库testdb具有的权限和用户user1一模一样。

gsql -r

CREATE ROLE user2 IDENTIFIED BY ‘kunpeng@1234’;

GRANT ALL ON DATABASE testdb TO user2;

omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=#   CREATE ROLE user2 IDENTIFIED BY 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=#   GRANT ALL ON DATABASE testdb TO user2;
GRANT
omm=#

–查看当前openGauss数据库集群由哪些用户：

\du

\q

omm=# \du
-----------+----------------------------------------------------------------------------------------------
--------------------+-----------
 gaussdb   | Sysadmin                                                                                     
                    | {}
 omm       | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin,
 Policyadmin, UseFT | {}
 user1     |                                                                                              
                    | {}
 user2     | Cannot login                                                                                 
                    | {}

                                                              List of roles
 Role name |                                                    Attributes                                
                    | Member of 
omm=# \q
omm@modb:~$

–使用用户user2尝试登录到数据库testdb：

gsql -d testdb -U user2 -W kunpeng@1234 -r

gsql: FATAL: role “user2” is not permitted to login

原因：
由于数据库用户user2是使用create role语句创建的，目前还不被允许登录到openGauss数据库管理系统.

omm@modb:~$  gsql -d testdb  -U user2  -W kunpeng@1234 -r
gsql: FATAL:  role "user2" is not permitted to login
omm@modb:~$

授予用户user2登录权限后：

授予用户user2登录权限后，可以登录数据库

gsql -r

alter user user2 LOGIN;

\du

\q

omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# alter user user2 LOGIN; 
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     |                                                                                              
                    | {}


 user2     |                                                                                              
                    | {}
omm=# \q
omm@modb:~$

–现在我们已经授予了user2用户登录数据库的权限，可以正常登录数据库testdb：

gsql -d testdb -U user2 -W kunpeng@1234 -r

\q

omm@modb:~$  gsql -d testdb   -U user2   -W kunpeng@1234 -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

testdb=> \q
omm@modb:~$

删除用户和角色

删除用户，首先需要将用户拥有的数据库对象转移或者删除，回收权限。

– 授予用户user2数据库超级用户的权限：

gsql -r

ALTER USER user2 SYSADMIN;

omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=#  ALTER USER user2 SYSADMIN;
ALTER ROLE
omm=#

–使用用户user2登录到数据库testdb，创建表空间test_tbs1、数据库testdb、表test1和表test2：

\c testdb user2

CREATE TABLESPACE test_tbs1 RELATIVE LOCATION ‘tablespace/test_tbs11’;

CREATE DATABASE testdb WITH TABLESPACE = test_tbs1;

CREATE TABLE test1(col int); CREATE TABLE test2(col int);

\q

omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=#  ALTER USER user2 SYSADMIN;
ALTER ROLE
omm=#  \c testdb user2
Password for user user2: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "testdb" as user "user2".
testdb=>  CREATE TABLESPACE test_tbs1 RELATIVE LOCATION 'tablespace/test_tbs11';
CREATE TABLESPACE
testdb=> CREATE DATABASE testdb WITH TABLESPACE = test_tbs1;
ERROR:  database "testdb" already exists
testdb=>  CREATE TABLE test1(col int);
CREATE TABLE
testdb=>  CREATE TABLE test2(col int);
testdb=> CREATE TABLE
testdb=> \q
omm@modb:~$

–执行如下的命令，删除用户user2：

gsql -r

drop user user2;

ERROR: role “user2” cannot be dropped because some objects depend on it DETAIL: owner of database testdb owner of tablespace test_tbs1 privileges for database testdb 2 objects in database testdb

###可以看出不能删除用户user2的原因是：
1）用户user2拥有数据库testdb。
2）用户user2拥有表空间对象test_tbs1。
3）用户user2对数据库testdb具有权限。
4）用户user2在数据库testdb中有两个对象。

omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=#  drop user user2;
ERROR:  role "user2" cannot be dropped because some objects depend on it
DETAIL:  owner of tablespace test_tbs1
privileges for database testdb
2 objects in database testdb
omm=#

–要删除用户user2，必须先表空间对象和数据库对象的属主修改为其他的用户（如user1用户），或者干脆将其删除：

alter database testdb owner to user1;

alter tablespace test_tbs1 owner to user1;

omm=#  alter database testdb owner to user1;
ALTER DATABASE
omm=# alter tablespace test_tbs1 owner to user1;
ALTER TABLESPACE
omm=#

–回收用户user2对testdb数据库的权限：

REVOKE ALL ON DATABASE testdb FROM user2;

omm=#  REVOKE ALL ON DATABASE testdb FROM user2;
REVOKE
omm=#

–在testdb中属于用户user2的数据库对象的处理方法可以是：假如该对象还有用，可以将该对象转移给其他用户；假如该对象没有用，可以直接删除掉该对象

–假设表test1已经没有用了，我们可以删除表test1：

\c testdb user2

drop table test1;

omm=# \c testdb user2
Password for user user2: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "testdb" as user "user2".
testdb=>  drop table test1;
DROP TABLE
testdb=>

–假设表test2还有用将表test2转移给用户user1：

REASSIGN OWNED BY user2 to user1;

\dt

\q

testdb=>  REASSIGN OWNED BY user2 to user1;
REASSIGN OWNED
testdb=> \dt
                         List of relations
 Schema | Name  | Type  | Owner |             Storage              
--------+-------+-------+-------+----------------------------------
 public | test2 | table | user1 | {orientation=row,compression=no}
(1 row)

testdb=> \q
omm@modb:~$

–执行删除用户的操作,可以删除user2用户

gsql -r

drop user user2;

\du

omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# drop user user2;
DROP ROLE
omm=# \du
 gaussdb   | Sysadmin                                                                                     
                    | {}
 omm       | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin,
 Policyadmin, UseFT | {}
 user1     |                                                                                              
                    | {}

                                                              List of roles
 Role name |                                                    Attributes                                
                    | Member of 
-----------+----------------------------------------------------------------------------------------------
--------------------+-----------
omm=#

课程作业

创建test10_tbs的表空间，在这个表空间中创建数据库testdb10

omm=# CREATE TABLESPACE test10_tbs RELATIVE LOCATION 'tablespace/test10_tbs1';
CREATE TABLESPACE
omm=# CREATE DATABASE testdb10 WITH TABLESPACE = test10_tbs;
CREATE DATABASE
omm=#

使用create user创建用户user10，登录数据库testdb10，创建测试表t1和t2

omm=# CREATE USER user10 IDENTIFIED BY 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# GRANT ALL ON DATABASE testdb10 TO user10;
GRANT
omm=# 
omm=# \q
omm@modb:~$ gsql -d testdb10   -U user10   -W kunpeng@1234 -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

testdb10=> 
testdb10=> \q
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# ALTER USER user10 SYSADMIN;
ALTER ROLE
omm=# \q
omm@modb:~$ gsql -d testdb10   -U user10   -W kunpeng@1234 -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

testdb10=> CREATE TABLE t1(col int);
CREATE TABLE
testdb10=> CREATE TABLE t2(col int);
CREATE TABLE
testdb10=>

使用create role创建角色role10，登录数据库testdb10

CREATE ROLE role10 IDENTIFIED BY 'kunpeng@1234';
GRANT ALL ON DATABASE testdb10 TO role10;
alter user role10 LOGIN;
gsql -d testdb10  -U role10  -W kunpeng@1234 -r

omm=> \q
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.
omm=> CREATE ROLE role10 IDENTIFIED BY 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# GRANT ALL ON DATABASE testdb10 TO role10;
GRANT
omm=#  gsql -d testdb10  -U role10  -W kunpeng@1234 -r
omm-# \q
omm@modb:~$  gsql -d testdb10  -U role10  -W kunpeng@1234 -r
gsql: FATAL:  role "role10" is not permitted to login
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.
omm=# alter user role10 LOGIN;
ALTER ROLE
omm=# \q
omm@modb:~$ gsql -d testdb10  -U role10  -W kunpeng@1234 -r  
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

testdb10=>

将表t1直接删除，将前面创建的表空间和数据库、表t2转给role10，删除用户user10

drop table t1;
REASSIGN OWNED BY user10 to role10;
alter database testdb10 owner to role10;
alter tablespace test10_tbs owner to role10;
alter table t2 owner to role10;
drop user user10;

omm=# \q
omm@modb:~$ gsql -d testdb10   -U user10   -W kunpeng@1234 -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

testdb10=> drop table t1;
DROP TABLE
testdb10=> 
testdb10=> \q
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# alter database testdb10 owner to role10;
ALTER DATABASE
omm=# alter tablespace test10_tbs owner to role10;
ALTER TABLESPACE
omm=# alter table t2 owner to role10;
ALTER TABLE
omm=# REASSIGN OWNED BY user10 to role10;
REASSIGN OWNED
omm=# 
omm=# drop user user10;
DROP ROLE
omm=#

最后删除role10

omm=# drop role role10;
ERROR:  role "role10" cannot be dropped because some objects depend on it
DETAIL:  owner of schema user10
owner of tablespace test10_tbs
owner of database testdb10
omm=# 
omm=# REVOKE ALL ON tablespace test10_tbs FROM role10;
REVOKE
omm=# drop OWNED BY role10;
DROP OWNED
omm=# drop database testdb10;
DROP DATABASE
omm=# drop role role10;
ERROR:  role "role10" cannot be dropped because some objects depend on it
DETAIL:  owner of tablespace test10_tbs
omm=# drop tablespace test10_tbs;
DROP TABLESPACE
omm=# drop role role10;
DROP ROLE
omm=#

课程学习体会

通过本次的实训操作，掌握数据库的使用create user创建的用户与使用create role创建的用户的区别，前者可以直接连接登录数据库，而使用create role创建的用户不能直接登录到数据库。必须添加LOGIN权限后，才能登录到数据库管理系统，而且删除用户，首先需要将用户拥有的数据库对象转移或者删除。

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