openGauss每日一练第6天 - 学习心得体会

原创 jianghu 2022-12-14

103

课后作业

环境准备：

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;
CREATE DATABASE musicdb1  WITH TABLESPACE = music_tbs;
CREATE DATABASE musicdb2  WITH TABLESPACE = music_tbs;复制

1.创建用户user1，分别在数据库musicdb1、数据库musicdb2创建表t11,t21

omm=# CREATE USER user1 IDENTIFIED BY 'kunpeng@1234';
ERROR:  role "user1" already exists
omm=#  
omm=# --授予user1数据库系统的SYSADMIN权限：
omm=# 
omm=# ALTER USER user1 SYSADMIN;
ALTER ROLE
omm=# 复制

\c musicdb1 user1

 create table t11(col1 char(20));
 insert into t11 values('Hello openGauss! 11');
 select * from t11;复制

2.user1用户连接到数据库musicdb1，并访问数据库musicdb1下的表t11

musicdb2=> \c musicdb1 user1
Password for user user1: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb1" as user "user1".
musicdb1=> select * from musicdb1.public.t11;
         col1         
----------------------
 Hello openGauss! 11 
(1 row)

musicdb1=> 复制

3.在这个连接中（使用数据库用户user1连接到数据库musicdb1）访问数据库musicdb2下的t21表(会报错)

4.使用数据库用户user1连接到数据库musicdb2，访问数据库musicdb2下的t21表。

musicdb1=> --可以正常访问，数据库中的表是存在的。但不能跨库访问。
\c musicdb2 user1
Password for user user1: 
FATAL:  Invalid username/password,login denied.
Previous connection kept
musicdb1=> \c musicdb2 user1
Password for user user1: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb2" as user "user1".
musicdb2=>  select * from musicdb2.public.t21;
         col1         
----------------------
 Hello openGauss! 22 
(1 row)复制