openGauss每日一练第4天 | openGauss中一个数据库可以被多个用户访问

学习目标

学习openGauss体系结构，使用多个用户访问同一个数据库

课程学习

创建用户1、用户2、用户3用户，验证数据库musicdb可以被用户user1、user2、user3访问（分别在数据库中创建了一张表、插入数据、进行查询）。即一个数据库可以被多个用户访问。

1.测试环境准备：

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=# drop database if exists musicdb;
NOTICE:  database "musicdb" does not exist, skipping(跳过)
DROP DATABASE
omm=# drop database if exists musicdb1;
NOTICE:  database "musicdb1" does not exist, skipping
DROP DATABASE
omm=# drop database if exists musicdb2;
NOTICE:  database "musicdb2" does not exist, skipping
DROP DATABASE
omm=# drop database if exists musicdb3;
NOTICE:  database "musicdb3" does not exist, skipping
DROP DATABASE
omm=# drop tablespace if exists music_tbs;
NOTICE:  Tablespace "music_tbs" does not exist, skipping.
DROP TABLESPACE
omm=# create tablespace music_tbs relative location 'tablespace/test_ts1';
CREATE TABLESPACE
omm=# create database musicdb with tablespace = music_tbs ;
CREATE DATABASE

2.创建用户用户1、用户2、用户3

--执行下面的SQL语句，创建用户user1、user2、user3：
omm=# create user user1 identified by 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# create user user2 identified by 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# create user user3 identified by 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
--授予user1、user2、user3数据库系统的SYSADMIN权限：
omm=# alter user user1 sysadmin;
ALTER ROLE
omm=# alter user user2 sysadmin;
ALTER ROLE
omm=# alter user user3 sysadmin;
ALTER ROLE
--执行下面的命令，查看有哪些用户：
omm=# \du
                                                              List of roles
 Role name |                                                    Attributes                                         
           | Member of 
-----------+-------------------------------------------------------------------------------------------------------
-----------+-----------
 gaussdb   | Sysadmin                                                                                              
           | {}
 omm       | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyad
min, UseFT | {}
 user1     | Sysadmin                                                                                              
           | {}
 user2     | Sysadmin                                                                                              
           | {}
 user3     | Sysadmin                                                                                              
           | {}

3.在终端中，分别使用user1、user2、user3用户访问数据库musicdb。

--以用户user1的身份在数据库musicdb中创建表t1，并插入一条数据：
omm=# \c musicdb user1
Password for user user1: 
musicdb=> Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb" as user "user1".

musicdb=> create table t1(col1 char(20));
CREATE TABLE
musicdb=> insert into t1 values('Hello kunpeng 1');
musicdb=> INSERT 0 1

musicdb=> select * from t1;
         col1         
----------------------
 Hello kunpeng 1     
(1 row)
--以用户user2的身份在数据库musicdb中创建表t2，并插入一条数据：
musicdb=> \c musicdb user2
Password for user user2: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb" as user "user2".
musicdb=> create table t2(col1 char(20));
CREATE TABLE
musicdb=> insert into t2 values('Hello kunpeng 2');
INSERT 0 1
musicdb=> select * from t2;
         col1         
----------------------
 Hello kunpeng 2     
(1 row)
--以用户user3的身份在数据库musicdb中创建表t3，并插入一条数据：
musicdb=> \c musicdb user3
Password for user user3: 
musicdb=> Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb" as user "user3".
create table t3(col1 char(20));
musicdb=> CREATE TABLE

musicdb=> insert into t3 values('Hello kunpeng 3');
musicdb=> INSERT 0 1

musicdb=> select * from t3;
         col1         
----------------------
 Hello kunpeng 3     
(1 row)

4.使用user1、user2、user3用户中的任何一个，执行如下命令，查看当前数据库musicdb有哪些表：

musicdb=> \dt

 public | t3   | table | user3 | {orientation=row,compression=no}
(3 rows)

musicdb=>                         List of relations
 Schema | Name | Type  | Owner |             Storage              
--------+------+-------+-------+----------------------------------
 public | t1   | table | user1 | {orientation=row,compression=no}
 public | t2   | table | user2 | {orientation=row,compression=no}

课后作业

1.创建用户用户A、userB、userC，授予userA、userB、userC数据库系统的SYSADMIN权限

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=# drop database if exists musicdb;
DROP DATABASE
omm=# drop database if exists musicdb1;
NOTICE:  database "musicdb1" does not exist, skipping
DROP DATABASE
omm=# drop database if exists musicdb2;
DROP DATABASE
omm=# NOTICE:  database "musicdb2" does not exist, skipping

omm=# drop database if exists musicdb3;
NOTICE:  database "musicdb3" does not exist, skipping
DROP DATABASE
omm=# drop tablespace if exists music_tbs;
omm=# DROP TABLESPACE
omm=# create tablespace music_tbs relative location 'tablespace/test_ts1';
CREATE TABLESPACE             ^
omm=# create database musicdb with tablespace = music_tbs ;
CREATE DATABASE
omm=# create user userA identified by 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# create user userB identified by 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# create user userC identified by 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# alter user userA sysadmin;
ALTER ROLE
omm=# alter user userB sysadmin;
omm=# ALTER ROLE
omm=# alter user userC sysadmin;
ALTER ROLE
omm=# \du
                                                              List of roles
 Role name |                                                    Attributes                                                    | Member of 
-----------+------------------------------------------------------------------------------------------------------------------+-----------
 gaussdb   | Sysadmin                                                                                                         | {}
omm=#  omm       | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin, UseFT | {}
 usera     | Sysadmin                                                                                                         | {}
 userb     | Sysadmin                                                                                                         | {}
 userc     | Sysadmin                                                                                                         | {}

2.分别使用userA、userB、userC访问数据库musicdb（如果未删除此库，可创建musicdb2库），创建各自的表，并插入数据。表名和数据如下：

表名分别为： 产品1、 产品2、 产品3

向表中插入数据：

omm=# \c musicdb userA
Password for user usera: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb" as user "usera".
musicdb=> create table products1(product_id INTEGER,product_name char(20),category char(30));
CREATE TABLE
musicdb=> insert into products1 valuesmusicdb-> (1502,'olympus camera','electrncs'),
musicdb-> (1601,'lamzae','toys'),musicdb-> (1700,'wait interface','books'),
musicdb-> (1666,'harry potter','toys');
INSERT 0 4
musicdb=> select * from products1 ;
 product_id |     product_name     |            category            
------------+----------------------+--------------------------------
       1502 | olympus camera       | electrncs                     
       1601 | lamzae               | toys                          
       1700 | wait interface       | books                         
       1666 | harry potter         | toys                          
(4 rows)
musicdb=> \c musicdb userB
Password for user userb: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb" as user "userb".
musicdb=>  create table products2 (product_id INTEGER,product_name char(20),category char(30));
CREATE TABLE
musicdb=> insert into products2 values
musicdb-> (1502,'olympus camera','electrncs'),
musicdb-> (1601,'lamzae','toys'),musicdb-> 
(1700,'wait interface','books'),
musicdb-> (1666,'harry potter','toys');
INSERT 0 4
musicdb=> select * from products2;
 product_id |     product_name     |            category            
------------+----------------------+--------------------------------
       1502 | olympus camera       | electrncs                     
       1601 | lamzae               | toys                          
       1700 | wait interface       | books                         
       1666 | harry potter         | toys                          
(4 rows)
musicdb=> \c musicdb userc
Password for user userc: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb" as user "userc".
musicdb=>  create table products3  (product_id INTEGER,product_name char(20),category char(30));
CREATE TABLE
musicdb=> insert into products3 values 
musicdb->  (1502,'olympus camera','electrncs'),musicdb-> 
(1601,'lamzae','toys'),
musicdb-> (1700,'wait interface','books'),
musicdb-> (1666,'harry potter','toys');
INSERT 0 4
musicdb=> select * from products3;
 product_id |     product_name     |            category            
------------+----------------------+--------------------------------
       1502 | olympus camera       | electrncs                     
       1601 | lamzae               | toys                          
       1700 | wait interface       | books                         
       1666 | harry potter         | toys                          
(4 rows)

3.使用userA、userB、userC用户中的任何一个，查看当前数据库musicdb有哪些表

musicdb=> \dt
                           List of relations
 Schema |   Name    | Type  | Owner |             Storage              
--------+-----------+-------+-------+----------------------------------
 public | products1 | table | usera | {orientation=row,compression=no}
 public | products2 | table | userb | {orientation=row,compression=no}
 public | products3 | table | userc | {orientation=row,compression=no}
(3 rows)