package com.demo.bean; public class Book {//教材 private long id; private String bookId;//教材ID private String name;//教材名称 private String price;//价格 private String author;//编者 private String publisher;//出版社 private String profession;//专业 private String channel;//渠道 private String appendix;//备注 public Book() {} public Book(long id, String bookId, String name, String price, String author, String publisher, String profession, String channel, String appendix) { this.id = id; this.bookId = bookId; this.name = name; this.price = price; this.author = author; this.publisher = publisher; this.profession = profession; this.channel = channel; this.appendix = appendix; } public long getId() { return id; } public void setId(long id) { this.id = id; } public String getBookId() { return bookId; } public void setBookId(String bookId) { this.bookId = bookId; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPrice() { return price; } public void setPrice(String price) { this.price = price; } public String getAuthor() { return author; } public void setAuthor(String author) { this.author = author; } public String getPublisher() { return publisher; } public void setPublisher(String publisher) { this.publisher = publisher; } public String getProfession() { return profession; } public void setProfession(String profession) { this.profession = profession; } public String getChannel() { return channel; } public void setChannel(String channel) { this.channel = channel; } public String getAppendix() { return appendix; } public void setAppendix(String appendix) { this.appendix = appendix; } @Override public String toString() { return "Book [id=" + id + ", bookId=" + bookId + ", name=" + name + ", price=" + price + ", author=" + author + ",

publisher=" + publisher + ", profession=" + profession + ", channel=" + channel + ", appendix=" + appendix + "]"; } }

这是一个 Java 类，表示一个教材（Book）对象，包括教材的 ID、名称、价格、编者、出版社、专业、渠道和备注等属性。其中包含了一个无参构造函数和一个有参构造函数，以及对应的 getter 和 setter 方法。此外，还重写了 toString 方法，以便于在需要打印该对象时，可以直接输出其属性值。

相关问题

<a href="${pageContext.request.contextPath}/book/toUpdateBook?id={book.bookID}">修改</a>

这是一个链接，当用户点击它时，会请求路径为"${pageContext.request.contextPath}/book/toUpdateBook?id={book.bookID}"的页面，其目的是修改相关的内容。

select book.id,book.name,max(dependDate) from book inner join bookEnrol on book.id=bookEnrol.bookid AND booker.state=1 group by book.id ;

这是一个 SQL 查询语句，查询的是书籍表中每本书最近一次被借阅的时间。

解释一下具体的查询逻辑：

1. `SELECT book.id, book.name, max(dependDate)` 选择需要查询的字段，包括书籍 ID、书籍名称和最近一次借阅时间（使用 `MAX` 函数获取最近的借阅日期）。

2. `FROM book` 从书籍表开始查询。

3. `INNER JOIN bookEnrol ON book.id = bookEnrol.bookid AND booker.state = 1` 与 `bookEnrol` 表连接，使用 `book.id = bookEnrol.bookid` 来找到对应的书籍信息，`booker.state = 1` 过滤出已被借阅的书籍。

4. `GROUP BY book.id` 将结果按照书籍 ID 进行分组，以便计算每本书最近一次被借阅的时间。

完整的查询语句如下：

SELECT book.id, book.name, max(dependDate)
FROM book
INNER JOIN bookEnrol ON book.id = bookEnrol.bookid AND booker.state = 1
GROUP BY book.id;