前言
上篇文章中，我们已经导入了book库，如果你还没有导入book库，参考：【跟晓月学数据库】使用MySQLdump 对数据导入导出
这篇文章，主要是基于book库的操作，希望对你有用。
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查看已经导入的book库的信息
[root@mufeng41 ~]# mysql -p'Root!2#admin'
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 5.7.42 MySQL Community Server (GPL)
Copyright (c) 2000, 2023, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| book |
| mysql |
| performance_schema |
| sys |
| test01 |
| test_db |
+--------------------+
7 rows in set (0.00 sec)
mysql>
mysql> use book
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> select * from category;
+---------+---------------+
| bTypeId | bTypeName |
+---------+---------------+
| 1 | windows应用 |
| 2 | 网站 |
| 3 | 3D动画 |
| 4 | linux学习 |
| 5 | Delphi学习 |
| 6 | 黑客 |
| 7 | 网络技术 |
| 8 | 安全 |
| 9 | 平面 |
| 10 | AutoCAD技术 |
+---------+---------------+
10 rows in set (0.00 sec)
查看表结构
mysql> desc books;
+------------+------------------------------------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------+------------------------------------------------+------+-----+---------+----------------+
| bId | int(4) | NO | PRI | NULL | auto_increment |
| bName | varchar(255) | YES | | NULL | |
| bTypeId | enum('1','2','3','4','5','6','7','8','9','10') | YES | | NULL | |
| publishing | varchar(255) | YES | | NULL | |
| price | int(4) | YES | | NULL | |
| pubDate | date | YES | | NULL | |
| author | varchar(30) | YES | | NULL | |
| ISBN | varchar(255) | YES | | NULL | |
+------------+------------------------------------------------+------+-----+---------+----------------+
8 rows in set (0.00 sec)
mysql> desc category;
+-----------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+-------------+------+-----+---------+----------------+
| bTypeId | int(4) | NO | PRI | NULL | auto_increment |
| bTypeName | varchar(40) | YES | | NULL | |
+-----------+-------------+------+-----+---------+----------------+
2 rows in set (0.00 sec)
mysql>
案例实战
- 查询价格大于50的图书名称和作者。
mysql> SELECT bName, author
-> FROM books
-> WHERE price > 50;
- 查询出版社为"电脑爱好者杂志社"的图书信息，包括图书名称、作者和出版日期。
SELECT bName, author, pubDate
FROM books
WHERE publishing = '电脑爱好者杂志社';
- 查询类别为"网站"的图书数量。
SELECT COUNT(*) AS book_count
FROM books
WHERE bTypeId IN (SELECT bTypeId FROM category WHERE bTypeName = '网站');
- 查询每个类别的平均价格，并按照平均价格降序排列。
SELECT c.bTypeName, AVG(b.price) AS avg_price
FROM category c
JOIN books b ON c.bTypeId = b.bTypeId
GROUP BY c.bTypeName
ORDER BY avg_price DESC;
- 查询发布日期在2022年1月1日到2022年12月31日之间的图书信息，包括图书名称和发布日期。
SELECT b.bName, b.pubDate, c.bTypeName
FROM books b
JOIN category c ON b.bTypeId = c.bTypeId
WHERE b.pubDate BETWEEN '2021-01-01' AND '2021-12-31' AND c.bTypeName = '网站';
- 查询价格在指定范围内（40-50），并且出版社为"航空工业出版社"的图书信息，包括图书名称、价格和出版社。
mysql> SELECT bName, price, publishing
-> FROM books
-> WHERE price BETWEEN 40 AND 50 AND publishing = '航空工业出版社';
+-----------------------+-------+-----------------------+
| bName | price | publishing |
+-----------------------+-------+-----------------------+
| 黑客与网络安全 | 41 | 航空工业出版社 |
+-----------------------+-------+-----------------------+
1 row in set (0.00 sec)
- 插入信息：
要向 “books” 表中增加一行数据，符合以下要求：
bTypeId：4
bTypeName：linux技术
bName=linux大全
publishing：互联网老辛出品
author：沐风晓月
pubDate：2023-03-27
price：88
ISBN：200001
INSERT INTO books (bTypeId, bName, publishing, price, pubDate, author, ISBN)
VALUES (4, 'linux大全', '互联网老辛出品', 88, '2023-03-27', '沐风晓月', '200001');
- 查询某个特定作者的图书信息：
mysql> SELECT bName, price, pubDate
-> FROM books
-> WHERE author = '沐风晓月';
+--------------+-------+------------+
| bName | price | pubDate |
+--------------+-------+------------+
| 填写书名 | 88 | 2023-03-27 |
| linux大全 | 88 | 2023-03-27 |
+--------------+-------+------------+
2 rows in set (0.01 sec)
- 查询所有图书的信息及其对应的出版社，包括图书名称、作者和出版社名称。如果某个图书没有对应的出版社，则显示为null。
SELECT b.bName, b.author, p.publishing
FROM books b
RIGHT JOIN publishing p ON b.publishingId = p.publishingId;
总结
关于MySQL的进阶实战，你学会了吗，欢迎评论区留言一起探讨。
