openGauss每日一练第 2 天|openGauss查询、更新和删除基本使用

1.创建一个表products

create table products(product_id INTEGER,product_name Char(20),category Char(10));

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

select * from products where product_id > 1600;

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

select * from products where category='toys';
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products