openGauss每日一练第4天 | 学习心得体会

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。

学习内容

本章节学习了使用多个用户访问一个数据库。

1.  创建一个表空间，再创建一个数据库，修改此数据库的默认表空间
2. 创建三个用户，并赋权sysadmin权限。
3. 使用三个用户分别登录新建数据库，创建三张表并插入数据再查看。
4. 最后，登录数据库使用\dt查看创建的三张表的信息，确认是否分别三个三个用户。

课后作业

1.创建用户user1、user2、user3，授予user1、user2、user3数据库系统的SYSADMIN权限

CREATE USER user11 IDENTIFIED BY 'test@1234';
CREATE USER user22 IDENTIFIED BY 'test@1234';
CREATE USER user33 IDENTIFIED BY 'test@1234';

授权sysadmin权限

ALTER USER user11 SYSADMIN;
ALTER USER user22 SYSADMIN;
ALTER USER user33 SYSADMIN;

查询结果

omm=# \du
                                                              List of roles
 Role name |                                                    Attributes                                              
      | Member of 
-----------+------------------------------------------------------------------------------------------------------------
 user11    | Sysadmin                                                                                                   
      | {}
 user22    | Sysadmin                                                                                                   
      | {}
 user33    | Sysadmin                                                                                                   
      | {}
 gaussdb   | Sysadmin                                                                                                   
      | {}
 omm       | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin, 
UseFT | {}

2.分别使用user1、user2、user3访问数据库musicdb2，创建各自的表，并插入数据。表名和数据如下：

表名分别为： products1、 products2、 products3

向表中插入数据：

创建数据库

CREATE DATABASE musicdb2;

用户1：创建表、插入数据查询

\c musicdb2 user11
create table products1(product_id integer,product_name char(20),category char(30));
insert into products1 values(1502,'olympus camera','electrncs'),(1601,'lamaze','toys'),(1700,'wait interface','Books'),(1666,'harry potter','toys');
select * from products1;

执行结果

omm=# \c musicdb2 user11
Password for user user11: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb2" as user "user11".
musicdb2=> create table products1(product_id integer,product_name char(20),category char(30));
CREATE TABLE
musicdb2=> insert into products1 values(1502,'olympus camera','electrncs'),(1601,'lamaze','toys'),(1700,'wait interface','Books'),(1666,'harry potter','toys');
INSERT 0 4
musicdb2=> select * from products1;
 product_id |     product_name     |            category            
------------+----------------------+--------------------------------
       1502 | olympus camera       | electrncs                     
       1601 | lamaze               | toys                          
       1700 | wait interface       | Books                         
       1666 | harry potter         | toys                          
(4 rows)

用用户2：创建表、插入数据查询

\c musicdb2 user22
create table products2(product_id integer,product_name char(20),category char(30));
insert into products2 values(1502,'olympus camera','electrncs'),(1601,'lamaze','toys'),(1700,'wait interface','Books'),(1666,'harry potter','toys');
select * from products2;

执行结果

omm=# \c musicdb2 user22
Password for user user22: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb2" as user "user22".
musicdb2=> create table products2(product_id integer,product_name char(20),category char(30));
CREATE TABLE
musicdb2=> insert into products2 values(1502,'olympus camera','electrncs'),(1601,'lamaze','toys'),(1700,'wait interface','Books'),(1666,'harry potter','toys');
INSERT 0 4
musicdb2=> select * from products2;
 product_id |     product_name     |            category            
------------+----------------------+--------------------------------
       1502 | olympus camera       | electrncs                     
       1601 | lamaze               | toys                          
       1700 | wait interface       | Books                         
       1666 | harry potter         | toys                          
(4 rows)

用用户3：创建表、插入数据查询

\c musicdb2 user33
create table products3(product_id integer,product_name char(20),category char(30));
insert into products3 values(1502,'olympus camera','electrncs'),(1601,'lamaze','toys'),(1700,'wait interface','Books'),(1666,'harry potter','toys');
select * from products3;

执行结果

omm=# \c musicdb2 user33
Password for user user33: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb2" as user "user33".
musicdb2=> create table products3(product_id integer,product_name char(20),category char(30));
CREATE TABLE
musicdb2=> insert into products3 values(1502,'olympus camera','electrncs'),(1601,'lamaze','toys'),(1700,'wait interface','Books'),(1666,'harry potter','toys');
INSERT 0 4
musicdb2=> select * from products3;
 product_id |     product_name     |            category            
------------+----------------------+--------------------------------
       1502 | olympus camera       | electrncs                     
       1601 | lamaze               | toys                          
       1700 | wait interface       | Books                         
       1666 | harry potter         | toys                          
(4 rows)

3.使用user1、user2、user3用户中的任何一个，查看当前数据库musicdb2有哪些表

\c musicdb2
\dt

执行结果

musicdb2=> \c musicdb2
Password for user user33: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb2" as user "user33".
musicdb2=> \dt
                           List of relations
 Schema |   Name    | Type  | Owner  |             Storage              
--------+-----------+-------+--------+----------------------------------
 public | products1 | table | user11 | {orientation=row,compression=no}
 public | products2 | table | user22 | {orientation=row,compression=no}
 public | products3 | table | user33 | {orientation=row,compression=no}
(3 rows)