openGauss每日一练第5天 | 用户可以访问不同的数据库

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

omm=# drop DATABASE  IF EXISTS  musicdb;
NOTICE:  database "musicdb" does not exist, skipping
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;
omm=# DROP TABLESPACE

omm=# CREATE TABLESPACE music_tbs RELATIVE LOCATION 'tablespace/test_ts1';
CREATE TABLESPACE
omm=# CREATE DATABASE musicdb2  WITH TABLESPACE = music_tbs;
CREATE DATABASE
omm=# CREATE DATABASE musicdb3  WITH TABLESPACE = music_tbs;
CREATE DATABASE
omm=# 

–执行下面的SQL语句，创建用户user1：

omm=#  CREATE USER user1 IDENTIFIED BY 'kunpeng@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE

–授予user1数据库系统的SYSADMIN权限：

ALTER ROLE

使用数据库用户user1登录到数据库musicdb1，创建一个表t11，并插入一条数据：
–用户user1登录到数据库musicdb1，创建表t11，并插入、查看数据

omm=#  \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=>  create table t11(col1 char(20));
CREATE TABLE
musicdb1=> insert into t11 values('Hello openGauss! 11');
INSERT 0 1
musicdb1=>  select * from t11;  
         col1         
----------------------
 Hello openGauss! 11 
(1 row) 

3.使用数据库用户user1登录到数据库musicdb2，创建一个表t21，并插入一条数据：

–用户user1登录到数据库musicdb2，创建表t21，并插入、查看数据

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=> create table t21(col1 char(20));
CREATE TABLE
musicdb2=>  insert into t21 values('Hello openGauss! 22');
INSERT 0 1
musicdb2=> select * from t21;
         col1         
----------------------
 Hello openGauss! 22 
(1 row)

4.使用数据库用户user1登录到数据库musicdb3，创建一个表t31，并插入一条数据：

–用户user1登录到数据库musicdb3，创建表t31，并插入、查看数据

musicdb2=> \c musicdb3 user1
Password for user user1: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb3" as user "user1".
musicdb3=> create table t31(col1 char(20));
CREATE TABLE
musicdb3=> insert into t31 values('Hello openGauss! 33');
INSERT 0 1
musicdb3=> select * from t31;
         col1         
----------------------
 Hello openGauss! 33 
(1 row)

课程作业

1.创建数据库musicdb10，创建用户user10，赋予sysadmin权限

musicdb3=> create database musicdb10 with tablespace=music_tbs;
CREATE DATABASE
musicdb3=> create user user10 identified by 'opengauss@123';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
musicdb3=> alter user user10 sysadmin;
ALTER ROLE

2.用户user10访问数据库postgres，创建一个表并插入数据

musicdb3=> \c postgres user10
Password for user user10: 
openGauss=> Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "postgres" as user "user10".
openGauss=> 
create table t1(id int,name varchar(20));
CREATE TABLE
openGauss=> insert into t1(1,'enmog');
ERROR:  syntax error at or near "1"
LINE 1: insert into t1(1,'enmog');
                       ^
openGauss=> insert into t1 values(1,'enmog');
INSERT 0 1
openGauss=> select * from t1;
 id | name  
----+-------
  1 | enmog
(1 row)

3.用户user10访问数据库omm，创建一个表并插入数据

openGauss=> \c omm user10
Password for user user10: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "omm" as user "user10".
omm=> create table t1(id integer,cname varchar(10));
CREATE TABLE
omm=> insert into t1 values(1,'mogdb3.0');  
INSERT 0 1
omm=> select * from t1;
 id |  cname   
----+----------
  1 | mogdb3.0
(1 row)

4.用户user10访问数据库musicdb10，创建一个表并插入数据

omm=> \c musicdb10 user10
Password for user user10: 
musicdb10=> Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb10" as user "user10".
musicdb10=> create table t2(c1 char(20),c2 int);
CREATE TABLE
musicdb10=> insert into t2 values('moddb3',10000);
INSERT 0 1
musicdb10=> select * from t2;
          c1          |  c2   
----------------------+-------
 moddb3               | 10000
(1 row)