openGauss每日一练第4天 - 学习心得体会

原创无心法师 2022-12-14

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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;

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;
DROP DATABASE
omm=# drop DATABASE  IF EXISTS  musicdb2;
DROP DATABASE
omm=# drop DATABASE  IF EXISTS  musicdb3;
NOTICE:  database "musicdb3" does not exist, skipping
DROP DATABASE
omm=# drop tablespace IF EXISTS music_tbs;
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=#

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

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=# ALTER USER user1 SYSADMIN; ALTER ROLE omm=# ALTER USER user2 SYSADMIN; ALTER ROLE omm=# ALTER USER user3 SYSADMIN; omm=# ALTER ROLE omm=# omm=# \du List of roles Role name | Attributes | Member of -----------+------------------------------------------------------------------------------------------------- -----------------+----------- gaussdb | Sysadmin | {} omm | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Po licyadmin, UseFT | {} user1 | Sysadmin | {} user3 | Sysadmin | {} user2 | Sysadmin | {} omm=#

2. 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;

omm=#  \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=> create table t1(col1 char(20));
CREATE TABLE
musicdb=>   insert into t1 values('Hello kunpeng 1');
INSERT 0 1
musicdb=> 
musicdb=>  select * from t1;
musicdb=>          col1         
----------------------
 Hello kunpeng 1     
(1 row)

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));
musicdb=> CREATE TABLE
insert into t2 values('Hello kunpeng 2');
INSERT 0 1
musicdb=>   select * from t2;
         col1         
----------------------
 Hello kunpeng 2     
(1 row)

musicdb=>  \c musicdb user3
Password for user user3: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb" as user "user3".
musicdb=> create table t3(col1 char(20));
CREATE TABLE
musicdb=> insert into t3 values('Hello kunpeng 3');
INSERT 0 1
musicdb=>   select * from t3;
         col1         
----------------------
 Hello kunpeng 3     
(1 row)

3. 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

musicdb=>  \dt                     
                        List of relations
 Schema | Name | Type  | Owner |             Storage              
--------+------+-------+-------+----------------------------------
 public | t1   | table | user1 | {orientation=row,compression=no}
 public | t2   | table | user2 | {orientation=row,compression=no}
 public | t3   | table | user3 | {orientation=row,compression=no}
(3 rows)