openGauss每日一练第 1 天 | 表的基础使用

1.创建一个表products
字段名 数据类型 含义
product_id INTEGER 产品编号
product_name Char(30) 产品名
category Char(20) 种类

omm=# create table products (product_id integer, product_name char(30),category char(20));
CREATE TABLE

2.向表中插入数据，采用一次插入一条和多条记录的方式
product_id product_name category
1502 olympus camera electrncs
1601 lamaze toys
1700 wait interface Books
1666 harry potter toys

omm=# insert into products values (1502,'olympus camera','electrncs');
INSERT 0 1
omm=# insert into products values (1601,'lamaze','toys'),(1700,'wait interface','Books'),(1666,'harry potter','toys');
INSERT 0 3

3.查询表中所有记录及记录数

omm=# select count(*) from products;
(1 row)

omm=#  count 
-------
     4

omm=# 
omm=# select * from products;
 product_id |          product_name          |       category       
------------+--------------------------------+----------------------
(4 rows)

omm=#        1502 | olympus camera                 | electrncs           
       1601 | lamaze                         | toys                
       1700 | wait interface                 | Books               
       1666 | harry potter                   | toys

4.查询表中所有category记录，并将查询结果按升序排序

omm=# select category from products  order by category;
(4 rows)

omm=#        category       
----------------------
 Books               
 electrncs           
 toys                
 toys 

5.查询表中category为toys的记录

omm=# select * from products where category='toys';
 product_id |          product_name          |       category       
------------+--------------------------------+----------------------
       1601 | lamaze                         | toys                
       1666 | harry potter                   | toys                
(2 rows)

6.删除表products
omm=# drop table products;
DROP TABLE