openGauss每日一练第 5 天| 学习心得体会

学习心得

很明显，本节课主要是为了复习，但我依然发现了有意思的地方，其实如果你已经连到了user10，切换库的时候，并不需要再指定用户，默认就是使用user10用户，而且当你连的是omm用户时，切换库的时候，并不需要输入密码，相当于Linux系统的root用户

课后作业

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

omm=# CREATE DATABASE musicdb10  WITH TABLESPACE = music_tbs;
CREATE DATABASE
omm=# create user user10 identified by 'test@123';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# alter user user10 sysadmin;
ALTER ROLE
omm=# 

2.用户user10访问数据库postgres，创建一个表并插入数据

omm=# \c postgres user10
Password for user user10: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "postgres" as user "user10".
openGauss=> select * from current_user;
openGauss=>  current_user 
--------------
 user10
(1 row)
openGauss=> create table xxs(i int);
CREATE TABLE
openGauss=> insert into xxs values(1);
INSERT 0 1
openGauss=> select * from xxs;
 i 
---
 1
(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: 
omm=> Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "omm" as user "user10".

omm=> create table xxs(i char(1));
CREATE TABLE
omm=> insert into xxs values('2');
INSERT 0 1
omm=> select * from xxs;
omm=>  i 
---
 2
(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: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb10" as user "user10".

musicdb10=> create table xxs(i number);
CREATE TABLE
musicdb10=> insert into xxs values(3);
INSERT 0 1
musicdb10=> select * from xxs;
 i 
---
 3
(1 row)