1.创建一个表products
CREATE TABLE products
( product_id integer,
product_name char(30),
category char(30)
) ;
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
(1502, 'olympus camera', 'electrncs'),
(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
\dt products
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 customer_t set c_customer_sk = c_customer_sk * 2 where c_customer_sk < 5000;
select * from products;
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;
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
drop products;
truncate table products;