《openGauss每日一练第二天|查询、更新和删除基本使用》

课后作业

1.创建一个表products

CREATE TABLE products
( product_id integer ,
product_name char(30),
category char(20)
) ;

2.向表中插入数据，采用一次插入一条和多条记录的方式

INSERT INTO products (product_id, product_name, category) VALUES (1502, 'olympus camera', 'electrncs');

INSERT INTO products (product_id, product_name, category) VALUES
(1601, 'lamaze', 'toys'),
(1700,'wait interface','Books'),
(1666,'harry potter','toys');

3.获取表中一条记录、三条记录和所有记录

select * from products limit 1;

select * from products limit 3;

select * from products;

4.将满足product_id > 1600的记录的product_id更新为product_id – 1000，并查看products中所有记录是否更新成功

update products set product_id=product_id-1000 where product_id > 1600;

select * from products;

5.删除category为toys的所有记录，并查看products中数据是否删除成功

delete from products where category='toys';

select * from products;

6.删除products中所有数据，并查看数据是否删除成功

delete from products;

select * from products;

7.删除表product

drop table products;