原创 openGauss每日一练第4天 | 3.0.0学习心得体会

原创手机用户6637 2022-11-27

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第四课

4.1 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user1、user2、user3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：

su - omm
gsql -r
--进入数据库omm，创建表空间、测试数据库
drop DATABASE  IF EXISTS  musicdb;
drop DATABASE  IF EXISTS  musicdb1;
drop DATABASE  IF EXISTS  musicdb2;
drop DATABASE  IF EXISTS  musicdb3;
drop tablespace IF EXISTS music_tbs;

CREATE TABLESPACE music_tbs RELATIVE LOCATION 'tablespace/test_ts1';
CREATE DATABASE musicdb  WITH TABLESPACE = music_tbs;
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2.创建用户user1、user2、user3

--执行下面的SQL语句，创建用户user1、user2、user3：

 CREATE USER user1 IDENTIFIED BY 'kunpeng@1234';
 CREATE USER user2 IDENTIFIED BY 'kunpeng@1234';
 CREATE USER user3 IDENTIFIED BY 'kunpeng@1234';
 
--授予user1、user2、user3数据库系统的SYSADMIN权限：

ALTER USER user1 SYSADMIN;
ALTER USER user2 SYSADMIN;
ALTER USER user3 SYSADMIN;

--执行下面的命令，查看有哪些用户：
 \du
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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：
 \c musicdb user1
  
  create table t1(col1 char(20));
  insert into t1 values('Hello kunpeng 1');
  select * from t1;
 
--以用户user2的身份在数据库musicdb中创建表t2，并插入一条数据：
  \c musicdb user2

  create table t2(col1 char(20));
  insert into t2 values('Hello kunpeng 2');
  select * from t2;


--以用户user3的身份在数据库musicdb中创建表t3，并插入一条数据：
  \c musicdb user3

  create table t3(col1 char(20));
  insert into t3 values('Hello kunpeng 3');
  select * from t3;
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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：

 \dt          
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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

omm=# --执行下面的SQL语句，创建用户user1、user2、user3：
omm=# 
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
omm=#  
omm=# --授予user1、user2、user3数据库系统的SYSADMIN权限：
omm=# 
omm=# ALTER USER user1 SYSADMIN;
ALTER ROLE
omm=# ALTER USER user2 SYSADMIN;
ALTER ROLE
omm=# ALTER USER user3 SYSADMIN;
ALTER ROLE
omm=# 
omm=# --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, Opera
toradmin, Policyadmin, UseFT | {}
 user1     | Sysadmin                                                                            
                             | {}
 user2     | Sysadmin                                                                            
                             | {}

                             | {}
 user3     | Sysadmin                                                                            
omm=# 
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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

字段名数据类型含义
product_id INTEGER 产品编号
product_name Char(20) 产品名
category Char(30) 种类
向表中插入数据：

product_id product_name category
1502 olympus camera electrncs
1601 lamaze toys
1700 wait interface Books
1666 harry potter toys

\c musicdb user1

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;

\c musicdb user2

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;

\c musicdb user3


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;

musicdb=> \c musicdb user1
Password for user user1: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb" as user "user1".
musicdb=> 
musicdb=> create table products1
musicdb-> (product_id INTEGER,
musicdb(> product_name char(20),
musicdb(> category char(30)
musicdb(> );
CREATE TABLE
musicdb=> insert into products1 values(1502,'olympus camera','electrncs'),
musicdb-> (1601,'lamaze','toys'),
musicdb-> musicdb-> (1700,'wait interface','Books'),
(1666,'harry potter','toys');
INSERT 0 4
musicdb=> 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)

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=> 
musicdb-> musicdb=> create table products2
(product_id INTEGER,
musicdb(> product_name char(20),
musicdb(> category char(30)
musicdb(> );
CREATE TABLE
musicdb=> insert into products2 values(1502,'olympus camera','electrncs'),
musicdb-> musicdb-> (1601,'lamaze','toys'),
(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 | lamaze               | toys                          
       1700 | wait interface       | Books                         
       1666 | harry potter         | toys                          
(4 rows)

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".

musicdb=> 
musicdb=> 
musicdb=> create table products3
musicdb-> (product_id INTEGER,
musicdb(> product_name char(20),
musicdb(> category char(30)
musicdb(> );
CREATE TABLE
musicdb=> insert into products3 values(1502,'olympus camera','electrncs'),
musicdb-> (1601,'lamaze','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 | lamaze               | toys                          


       1700 | wait interface       | Books                         
       1666 | harry potter         | toys                          
(4 rows)musicdb=> 
musicdb=> 
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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


\dt
select * from products1;


musicdb=> \dt
                           List of relations
 Schema |   Name    | Type  | Owner |             Storage              
--------+-----------+-------+-------+----------------------------------
 public | products1 | table | user1 | {orientation=row,compression=no}
 public | products2 | table | user2 | {orientation=row,compression=no}
 public | products3 | table | user3 | {orientation=row,compression=no}
(3 rows)

musicdb=> 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)

musicdb=> 

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