1.做一个图书类Book id,name,price 。 get,set访问器,构造方法2个,1个无参,1个有参

package homework;

public class lcx {
    private String id;
    private String name;
    private double price;
    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public lcx(String string, String name, double price) {
        super();
        this.id = string;
        this.name = name;
        this.price = price;
    }

    public lcx() {
        super();
    }

}

  做一个测试类,在main中创建3个图书对象,放到list集合中。做一个菜单,可以添加,删除,修改,查询

package homework;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class lcxtext {
    static List<lcx> listbooks = new ArrayList<lcx>();

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        creatBookList();
        menu();

    }

    public static void creatBookList() {
        // TODO Auto-generated method stub
        lcx b1 = new lcx("001", "葵花宝典", 9.99);
        listbooks.add(b1);
        lcx b2 = new lcx("002", "十二路弹腿", 19.99);
        listbooks.add(b2);
        lcx b3 = new lcx("003", "玉女心经", 29.9);
        listbooks.add(b3);
    }

    public static void menu() {
        for (;;) {
            System.out.println("************************");
            System.out.println("*       1.添加图书          *");
            System.out.println("*       2.修改图书          *");
            System.out.println("*       3.删除图书          *");
            System.out.println("*       4.查询图书          *");
            System.out.println("*       5.退出程序          *");
            System.out.println("************************");
            int a = inputInt("请选择你的操作:");
            switch (a) {
            case 1:
                addBook();
                break;
            case 2:
                updateBook();
                break;
            case 3:
                delBook();
                break;
            case 4:
                findBook();
                break;
            case 5:
                return;
            default:
                System.out.println("输入错误,请重新输入");
                break;
            }
        }
    }

    private static void findBook() {
        // TODO Auto-generated method stub
        System.out.println("id   图书名称  图书价格");
        for (lcx book : listbooks) {
            System.out.println(book.getId() + " " + book.getName() + "    "
                    + book.getPrice());
        }

    }

    private static void delBook() {
        // TODO Auto-generated method stub
        String id = inputStr("请输入要删除图书的id");
        for (int i = 0; i < listbooks.size(); i++) {
            lcx book = listbooks.get(i);
            if (id.equals(book.getId())) {
                listbooks.remove(i);
            }
        }

    }

    private static void updateBook() {
        // TODO Auto-generated method stub
        String id = inputStr("请输入要修改的图书id");
        for (int i = 0; i < listbooks.size(); i++) {
            lcx book = listbooks.get(i);
            if (id.equals(book.getId())) {
                book.setName(inputStr("请输入修改后的图书名称:"));
                book.setPrice(inputDouble("请输入修改后的图书价格"));
                listbooks.remove(i);
                listbooks.add(i, book);
            }
        }

    }

    private static void addBook() {
        // TODO Auto-generated method stub
        String id = inputStr("请输入要添加的图书id");
        String name = inputStr("请输入要添加的图书名称");
        double price = inputDouble("请输入要添加的图书价格");
        lcx book = new lcx(id, name, price);
        listbooks.add(book);

    }

    public static String inputStr(String msg) {
        System.out.print(msg);
        return new Scanner(System.in).nextLine();
    }

    public static int inputInt(String msg) {
        System.out.print(msg);
        return new Scanner(System.in).nextInt();
    }

    public static double inputDouble(String msg) {
        System.out.print(msg);
        return new Scanner(System.in).nextDouble();
    }

}

  

 

 

 

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ page import="homework.lcx"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'index.jsp' starting page</title>
</head>

<body>
    <%
        List<lcx> listbooks = new ArrayList<lcx>();
 Book b1 = new Book("1", "网络安全技术", 79.0);
        listbooks.add(b1);
        Book b2 = new Book("2", "JSP实用教程", 59.8);
        listbooks.add(b2);
        Book b3 = new Book("3", "JavaScript", 49.8);
        listbooks.add(b3);
listbooks.add(b3); for (int i = 0; listbooks != null && i < listbooks.size(); i++) { out.print(listbooks.get(i).getId() + ": " + listbooks.get(i).getName() + " " + listbooks.get(i).getPrice() + "<br>"); } %> </body> </html>

  

3.在MySQL中创建Book表,里面id,name,price,

用命令实现,
添加5个图书,
把20元以上的图书价格都修改为18.8,
查看全部图书,
查看价格高于10块钱的全部图书
根据名称删除图书,
把所有名称是“我”开头的图书删除,
删除全部图书。
insert into 表名(列,列,列)values(值,值,值)
delete from 表名 where 删除条件
update 表名 set列名=更新值 where 更新条件
select 列,列,列 …… from 表 where 查询条件

在MYSQL中创建Book表,里面id,name,price    create table book(
    -> id int(10) auto_increment primary key,
    -> name varchar(50),
    -> price double(5,1));
添加5个图书
 insert into Book(id,name,price)values(1,"小王子",9.5);
 insert into Book(id,name,price)values(2,"web",20);
 insert into Book(id,name,price)values(3,"HTML",30);
 insert into Book(id,name,price)values(4,"水浒传",28);
 insert into Book(id,name,price)values(5,"梦想家",17);
把20元以上的图书价格都修改为18.8,
 update book set price=18.8 where price>20;
查看全部图书
 select *from book;
查看价格高于10块的全部图书
 select * from book where price>10;
把所有名称是“我”开头的图书删除
 delete from book where name like '我%';
删除全部图书
 delete from book;

  

 

posted on 2022-05-01 15:04  李昌璇  阅读(8)  评论(0编辑  收藏  举报