openGauss每日一练第11天|课后作业

课程作业

1.为系统表PG_DATABASE创建视图，重命名视图并修改owner为jim
创建视图view1

CREATE VIEW view1 AS
SELECT * FROM PG_DATABASE;

创建用户jim，重命名视图view1为view2并修改owner为jim

CREATE USER jim PASSWORD 'gauss@123';
ALTER VIEW view1 RENAME TO view2;
ALTER VIEW view2 owner to jim;

2.创建一个用户表student，并在用户表上创建视图，修改视图schema;

Create schema tpcds;
CREATE TABLE tpcds.student
(  id        integer,      
   name      char(10)   
) ;
INSERT INTO tpcds.student VALUES    
(1, 'Joes'),    
(2, 'Lily'),    
(3, 'James'),
(4, 'Lucy');
CREATE VIEW tpcds.student_view AS
SELECT * FROM tpcds.student;

修改schema

ALTER VIEW tpcds.student_view SET schema public;

3.使用pg_views查看视图信息

select * from pg_views where viewname = 'student_view';

4.删除视图、表、用户

DROP VIEW student_view;
DROP VIEW view2;

5.总结
视图好比一张“虚表”，今天学习了其基本的操作。
前面准备期末考试断了，今天再次继续打卡，奥里给xdm！