课程学习
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。
# 1.环境准备
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
omm=# # 2.使用create user创建用户
�予用户user1: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
omm=#
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:
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 +
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:
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
-bash: $'--\347\224\250\345\210\232\345\210\232\345\210\233\345\273\272\347\232\204\346\225\260\346\215\256\345\272\223\347\224\250\346\210\267user1\347\231\273\345\275\225\345\210\260\346\225\260\346\215\256\345\272\223testdb': command not found
omm@modb:~$ 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 # 3.使用create role创建用户
--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;
--查看当前openGauss数据库集群由哪些用户:
\du
\q
--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
omm=# 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=#
omm=#
omm=# \du
--查看当前openGauss数据库集群由哪些用户:
omm=# List of roles
Role name | Attributes
| Member of
-----------+------------------------------------------------------------------------------------------------------------
------+-----------
gaussdb | Sysadmin
| {}
omm | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin,
UseFT | {}
user2 | Cannot login
| {}
user1 |
| {}
omm=# \q
omm@modb:~$
omm@modb:~$ --使用用户user2尝试登录到数据库testdb:
-bash: $'--\344\275\277\347\224\250\347\224\250\346\210\267user2\345\260\235\350\257\225\347\231\273\345\275\225\345\210\260\346\225\260\346\215\256\345\272\223testdb\357\274\232': command not found
omm@modb:~$ gsql -d testdb -U user2 -W kunpeng@1234 -r
gsql: FATAL: role "user2" is not permitted to login
omm@modb:~$ omm@modb:~$
gsql: FATAL: role "user2" is not permitted to login
-bash: gsql:: command not found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。
# 4.授予用户user2登录权限后:
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=#
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:
-bash: $'--\347\216\260\345\234\250\346\210\221\344\273\254\345\267\262\347\273\217\346\216\210\344\272\210\344\272\206user2\347\224\250\346\210\267\347\231\273\345\275\225\346\225\260\346\215\256\345\272\223\347\232\204\346\235\203\351\231\220\357\274\214\345\217\257\344\273\245\346\255\243\345\270\270\347\231\273\345\275\225\346\225\260\346\215\256\345\272\223testdb\357\274\232': command not found
omm@modb:~$ 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# 5.删除用户和角色
-- 授予用户user2数据库超级用户的权限:
gsql -r
ALTER USER user2 SYSADMIN;
--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
--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
omm@modb:~$ -- 授予用户user2数据库超级用户的权限:
-bash: --: command not found
gsql -r
omm@modb:~$ 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=#
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
omm=# 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);
CREATE TABLE
testdb=> \q
omm@modb:~$ --执行如下的命令,删除用户user2:
-bash: $'--\346\211\247\350\241\214\345\246\202\344\270\213\347\232\204\345\221\275\344\273\244\357\274\214\345\210\240\351\231\244\347\224\250\346\210\267user2\357\274\232': command not found
omm@modb:~$ 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=#
omm=# ERROR: role "user2" cannot be dropped because some objects depend on it
omm-# DETAIL: owner of database testdb
omm-# owner of tablespace test_tbs1
omm-# privileges for database testdb
omm-# 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。--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;
--回收用户user2对testdb数据库的权限:
REVOKE ALL ON DATABASE testdb FROM user2;
--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;
--假设表test2还有用将表test2转移给用户user1:
REASSIGN OWNED BY user2 to user1;
\dt
\q
--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 ((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-#
omm-#
omm-# omm-#
omm-#
omm-#
omm-#
omm-# omm-#
omm-#
omm-#
omm-#
omm-#
户),或者干脆将其删除: 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�
omm-# alter database testdb owner to user1;
ERROR: syntax error at or near "ERROR"
LINE 1: ERROR: role "user2" cannot be dropped because some objects ...
^
omm=# alter tablespace test_tbs1 owner to user1;
ALTER TABLESPACE
omm=#
omm=# --回收用户user2对testdb数据库的权限:
omm=# REVOKE ALL ON DATABASE testdb FROM user2;
REVOKE
omm=#
�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:假如该对象还有用,可以将该
omm=#
omm=# --假设表test1已经没有用了,我们可以删除表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=> 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
-bash: $'--\346\211\247\350\241\214\345\210\240\351\231\244\347\224\250\346\210\267\347\232\204\346\223\215\344\275\234,\345\217\257\344\273\245\345\210\240\351\231\244user2\347\224\250\346\210\267': command not found
omm@modb:~$ 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
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=# 



