进入实训环境

su - omm
gsql -r

1.创建一个表products

使用CREATE TABLE

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

插入一个

INSERT INTO products VALUES
(1502, ‘olympus camera’, ‘electrncs’);

插入多个

INSERT INTO products VALUES
(1601, ‘lamaze’,‘toys’),
(1700, ‘wait interface’, ‘Books’),
(1666, ‘harry potter’, ‘toys’);

3.查询表中所有记录及记录数

查询记录数 count

select count(*) from products;

count
-------
4
(1 row)

查询记录

select * from products;

product_id | product_name | category

------------±-------------------------------±---------------------
1502 | olympus camera | electrncs
1601 | lamaze | toys
1700 | wait interface | Books
1666 | harry potter | toys
(4 rows)

4.查询表中所有category记录，并将查询结果按升序排序

select * from products order by category;

product_id | product_name | category
------------±-------------------------------±---------------------

1700 | wait interface | Books
1502 | olympus camera | electrncs
1601 | lamaze | toys
1666 | harry potter | toys
(4 rows)

5.查询表中category为toys的记录

select * from products where category = ‘toys’;

product_id | product_name | category
------------±-------------------------------±---------------------
1666 | harry potter | toys
1product_id | product_name | category

------------±-------------------------------±---------------------
1601 | lamaze | toys
1666 | harry potter | toys
(2 rows)

6.删除表products

drop table products;

DROP TABLE