数据库学生信息管理系统

设计任务：
本管理系统基于学生表进行数据的存储和读取，首先由一个登陆界面，输入正确的学生的学号和密码才能进入系统，如果学生登陆成功，曾通过菜单命令显示所有学生信息、添加学生、插入学生、删除学生、根据姓名查询学生信息，查看学生平均成绩和成绩统计
分析等。

需求分析：
用户需要一个用户登录系统以保证数据库的隐私，通过姓名学号检验是否有登录权限，之后设计一个主页面，设计简易下拉框来实现页面简洁性，下拉框包括查询，查询包括按姓名查询，ID查询；更新功能，更新功能又可实现数据的增加，删除，修改，这可以再通过一个小窗口实现；成绩查询，学生平均分显示，不及格人数查询，优秀人数查询。这就是一个简单的学生信息管理系统。

细节分析

标题通过sql语句创建数据库，建立需要的表，同时插入所需要的的数据，然后建立数据库连接类，使用JDBC连接数据库需要四步，第一步加载驱动程序；第二步，连接数据库；第三步，访问数据库；第四步，执行查询；其中在第四步执行查询时，要用statement类的executeQuery()方法来下达select指令以查询数据库，executeQuery()方法会把数据库响应的查询结果存放在ResultSet类对象中供我们使用。建立好数据库连接类后开始实现所需要的功能的类，先将要使用的Connection con，PreparedStatement pstat，ResultSet rs变量定义好，首先是查询类，通过姓名进行查询，通过ID进行查询，查询全部，然后调用连接类连接oracle数据库，再通过查找所需要的对应的sql语句设置查找条件，再对返回的结果集进行处理，最后关闭数据库；紧接着是修改类，然后调用连接类连接oracle数据库，再通过修改信息所需要的对应的sql语句设置修改条件，再对返回的结果集进行处理，这里设置返回结果为布尔型，便于用户看到修改是否成功，最后关闭数据库；之后是增加学生类，然后调用连接类连接oracle数据库，再通过增加信息所需对应的sql语句设置增加条件，再对返回的结果集进行处理，这里设置返回结果为布尔型，便于用户看到增加是否成功，最后关闭数据库。之后是删除类，然后调用连接类连接oracle数据库，再通过删除信息所需对应的sql语句设置删除条件，再对返回的结果集进行处理，这里设置返回结果为布尔型，便于用户看到删除是否成功，最后关闭数据库。第五步，实现用户窗体页面，创建登录窗体类，通过调用查询类查询用户密码是否存在，再创建主窗体类，登陆成功后进入主窗体，主窗体包括查询，更改，删除，增加的一个下拉框，平均成绩，成绩统计的一个下拉框。通过设置button按钮监听，实现对各个功能类的调用。最后达到用户的需求。

#附部分功能截图

备注：需完整word请到主页下载。

学生信息管理系统内容：
学生表student(Sno,Sname,Ssex,Sage,Sdept)
课程表course(Cno,Cname,Cpno,Ccredit)
学生选课表SC(Sno,Cno,Grade)

一、 创建数据库并使用

mysql> use dx;
Database changed

二、 创建数据库表并显示数据课表结构

学生选课表SC(Sno,Cno,Grade)

mysql> create table SC
    -> (Sno varchar(255),
    -> Cno varchar(255),
    -> Grade smallint
    -> );
Query OK, 0 rows affected (0.06 sec)

mysql> desc sc;
+-------+--------------+------+-----+---------+-------+
| Field | Type         | Null | Key | Default | Extra |
+-------+--------------+------+-----+---------+-------+
| Sno   | varchar(255) | YES  |     | NULL    |       |
| Cno   | varchar(255) | YES  |     | NULL    |       |
| Grade | smallint(6)  | YES  |     | NULL    |       |
+-------+--------------+------+-----+---------+-------+
3 rows in set (0.05 sec)

mysql>

学生表student(Sno,Sname,Ssex,Sage,Sdept)

mysql> create table student(Sno varchar(255),Sname varchar(255),Sage int,Sdept varchar(255));
Query OK, 0 rows affected (0.08 sec)

mysql> desc student;
+-------+--------------+------+-----+---------+-------+
| Field | Type         | Null | Key | Default | Extra |
+-------+--------------+------+-----+---------+-------+
| Sno   | varchar(255) | YES  |     | NULL    |       |
| Sname | varchar(255) | YES  |     | NULL    |       |
| Sage  | int(11)      | YES  |     | NULL    |       |
| Sdept | varchar(255) | YES  |     | NULL    |       |
+-------+--------------+------+-----+---------+-------+
4 rows in set (0.01 sec)

mysql>

课程表course(Cno,Cname,Cpno,Ccredit)

mysql> create table course(Cno varchar(255),Cname varchar(255),Cpno int,Ccredit varchar(255));
Query OK, 0 rows affected (0.09 sec)

mysql> desc course;
+---------+--------------+------+-----+---------+-------+
| Field   | Type         | Null | Key | Default | Extra |
+---------+--------------+------+-----+---------+-------+
| Cno     | varchar(255) | YES  |     | NULL    |       |
| Cname   | varchar(255) | YES  |     | NULL    |       |
| Cpno    | int(11)      | YES  |     | NULL    |       |
| Ccredit | varchar(255) | YES  |     | NULL    |       |
+---------+--------------+------+-----+---------+-------+
4 rows in set (0.01 sec)

显示数据库中是数据库表：

mysql> show tables;
+--------------+
| Tables_in_dx |
+--------------+
| course       |
| sc           |
| student      |
+--------------+
3 rows in set (0.00 sec)

三、 在数据库表中插入数据

在数据库表SC中插入数据：

mysql>  insert into SC values('20161018','1',90);
Query OK, 1 row affected (0.00 sec)

mysql>  insert into SC values('20161019','2',90);
Query OK, 1 row affected (0.00 sec)

mysql>  insert into SC values('20161020','3',100);
Query OK, 1 row affected (0.00 sec)

mysql>  insert into SC values('20161021','4',89);
Query OK, 1 row affected (0.00 sec)

mysql> select * from SC;
+----------+------+-------+
| Sno      | Cno  | Grade |
+----------+------+-------+
| 20161018 | 1    |    90 |
| 20161019 | 2    |    90 |
| 20161020 | 3    |   100 |
| 20161021 | 4    |    89 |
+----------+------+-------+
4 rows in set (0.00 sec)

其他数据库表插入数据也一样，不过需要注意的是变量的形式（字符型、整型、浮点数）

mysql> select * from student;
+----------+-------+------+------+-------+
| Sno      | Sname | Ssex | Sage | Sdept |
+----------+-------+------+------+-------+
| 20161018 | 里勇  | 男   |   20 | CS    |
| 20161019 | 刘成  | 女   |   19 | IS    |
| 20161020 | 王敏  | 女   |   19 | MA    |
| 20161021 | 张里  | 男   |   18 | MA    |
+----------+-------+------+------+-------+
4 rows in set (0.00 sec)

mysql> select Sno,Sname from student;
+----------+-------+
| Sno      | Sname |
+----------+-------+
| 20161018 | 里勇  |
| 20161019 | 刘成  |
| 20161020 | 王敏  |
| 20161021 | 张里  |
+----------+-------+
4 rows in set (0.00 sec)

mysql> select Sname,2016-Sage from student;
+-------+-----------+
| Sname | 2016-Sage |
+-------+-----------+
| 里勇  |      1996 |
| 刘成  |      1997 |
| 王敏  |      1997 |
| 张里  |      1998 |
+-------+-----------+
4 rows in set (0.00 sec)

mysql> select * from course;
+-----+----------+------+---------+
| Cno | Cname    | Cpno | Ccredit |
+-----+----------+------+---------+
| 1   | 高数     | 1    |       6 |
| 2   | 大物     | 2    |       4 |
| 3   | 数电     | 3    |       6 |
| 4   | 大学英语 | 4    |       5 |
| 5   | 数据库   | 5    |       3 |
+-----+----------+------+---------+
5 rows in set (0.04 sec)

四、将数据库表进行改名

mysql> select Sname as 姓名,'Year of Birth:',2016-Sage 出生年份,lower(Sdept) 学院 from student;
+------+----------------+----------+------+
| 姓名 | Year of Birth: | 出生年份 | 学院 |
+------+----------------+----------+------+
| 里勇 | Year of Birth: |     1996 | cs   |
| 刘成 | Year of Birth: |     1997 | is   |
| 王敏 | Year of Birth: |     1997 | ma   |
| 张里 | Year of Birth: |     1998 | ma   |
+------+----------------+----------+------+
4 rows in set (0.00 sec)

五、 对数据库表进行各种操作

mysql> select Sno from SC;
+----------+
| Sno      |
+----------+
| 20161018 |
| 20161019 |
| 20161020 |
| 20161021 |
+----------+
4 rows in set (0.00 sec)

mysql> select distinct Grade from SC;
+-------+
| Grade |
+-------+
|    90 |
|   100 |
|    89 |
+-------+
3 rows in set (0.00 sec)

mysql> select distinct Sno from SC where Grade > 90;
+----------+
| Sno      |
+----------+
| 20161020 |
+----------+
1 row in set (0.00 sec)

mysql> select Sname,Ssex
    -> from student
    -> where Sdept = 'IS' or Sdept = 'MA' or Sdept = 'CS';
+-------+------+
| Sname | Ssex |
+-------+------+
| 里勇  | 男   |
| 刘成  | 女   |
| 王敏  | 女   |
| 张里  | 男   |
+-------+------+
4 rows in set (0.00 sec)

mysql> select count(*) from student;
+----------+
| count(*) |
+----------+
|        4 |
+----------+
1 row in set (0.00 sec)

mysql> select avg(Grade) from SC;
+------------+
| avg(Grade) |
+------------+
|    92.2500 |
+------------+
1 row in set (0.00 sec)

mysql> select Cno,count(Sno)
    -> from SC
    -> group by Cno;
+------+------------+
| Cno  | count(Sno) |
+------+------------+
| 1    |          1 |
| 2    |          1 |
| 3    |          1 |
| 4    |          1 |
+------+------------+
4 rows in set (0.00 sec)

mysql> select Cno,avg(Grade)
    -> from SC
    -> group by Cno;
+------+------------+
| Cno  | avg(Grade) |
+------+------------+
| 1    |    90.0000 |
| 2    |    90.0000 |
| 3    |   100.0000 |
| 4    |    89.0000 |
+------+------------+
4 rows in set (0.00 sec)
mysql> select student.*,sc.*
    -> from student,sc
    -> where student.Sno = sc.Sno;
+----------+-------+------+------+-------+----------+------+-------+
| Sno      | Sname | Ssex | Sage | Sdept | Sno      | Cno  | Grade |
+----------+-------+------+------+-------+----------+------+-------+
| 20161018 | 里勇  | 男   |   20 | CS    | 20161018 | 1    |    90 |
| 20161019 | 刘成  | 女   |   19 | IS    | 20161019 | 2    |    90 |
| 20161020 | 王敏  | 女   |   19 | MA    | 20161020 | 3    |   100 |
| 20161021 | 张里  | 男   |   18 | MA    | 20161021 | 4    |    89 |
+----------+-------+------+------+-------+----------+------+-------+
4 rows in set (0.00 sec)

mysql> select student.Sno,Sname,Ssex,Sage,Sdept,Cno,Grade
    -> from student,sc
    -> where student.Sno = sc.Sno;
+----------+-------+------+------+-------+------+-------+
| Sno      | Sname | Ssex | Sage | Sdept | Cno  | Grade |
+----------+-------+------+------+-------+------+-------+
| 20161018 | 里勇  | 男   |   20 | CS    | 1    |    90 |
| 20161019 | 刘成  | 女   |   19 | IS    | 2    |    90 |
| 20161020 | 王敏  | 女   |   19 | MA    | 3    |   100 |
| 20161021 | 张里  | 男   |   18 | MA    | 4    |    89 |
+----------+-------+------+------+-------+------+-------+
4 rows in set (0.00 sec)

mysql> select student.Sno,Sname,Cname,Grade
    -> from student,sc,course
    -> where student.Sno = sc.Sno and sc.Cno = course.Cno;
+----------+-------+----------+-------+
| Sno      | Sname | Cname    | Grade |
+----------+-------+----------+-------+
| 20161018 | 里勇  | 高数     |    90 |
| 20161019 | 刘成  | 大物     |    90 |
| 20161020 | 王敏  | 数电     |   100 |
| 20161021 | 张里  | 大学英语 |    89 |
+----------+-------+----------+-------+
4 rows in set (0.00 sec)

mysql>

这篇博文主要是利用数据库对学生信息进行管理，它可以利用各种操作对学生信息进行增删减查，非常的方便！！！

当然最重要的是你自己动手去做，不然一切免谈，也不要指望着别人。。。嘻嘻嘻。。。送我个赞呗。。。

各位老铁们，给我个三连击呗，可以让更多的人看到这篇文章，同时也激励一下我
各位老铁们，给我个三连击呗，可以让更多的人看到这篇文章，同时也激励一下我
各位老铁们，给我个三连击呗，可以让更多的人看到这篇文章，同时也激励一下我

简单介绍：

这次的项目是用数据库实现学生的信息管理系统，有三步组成，写项目>>链接数据库>>实现相关的操作

开发工具：eclipse、MySQL、navicat、mysql-connector-java-8.0.27

1.数据库建表

-- 创建数据库
CREATE DATABASE niit
DEFAULT CHARACTER SET utf8mb4;

SHOW DATABASES;

-- 使用数据库niit
USE niit;

-- 创建表Student
CREATE TABLE Student
(
	ID INT PRIMARY KEY, 
	NAME VARCHAR(4),
	GENDER CHAR(1),
	DOB DATE,
	BATCH INT
);

-- 插入记录
INSERT INTO Student VALUES
(1,'张','男','1988-1-2',1),
(2,'李四','女','1988-12-3',1),
(3,'王五','男','1978-11-1',1),
(4,'若若','女','1989-2-5',2),
(5,'夏春','女','1998-4-3',2),
(6,'梅花','女','1999-12-6',2);

-- 查看表中所有记录 语法：select * from 表名
SELECT * FROM Student;

2，相关代码（主页面+增删查改）

（1）主页面

package studentManage;

import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Font;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class MainFrame extends JFrame {

	private JPanel contentPane;

	/**
	 * Launch the application.
	 */
	// 有了main函数才可以单独运行
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					MainFrame frame = new MainFrame();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public MainFrame() {
		// 设置大小不可改变
		setResizable(false);
		// 设置标题
		setTitle("学生管理系统");
		// 由于这是主页面，所有当主页面关闭的时候，程序就直接退出
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		// setBounds(int x,int y,int width,int height);
		// x 和 y 是窗口打开时的位置
		// width 和 height 是窗口打宽度和高度
		setBounds(100, 100, 450, 350);
		// setLocationRelativeTo(c)
		// 设置窗口相对于 c 的位置，当 c 为空或者 null 时，默认为是相对于屏幕中央
		setLocationRelativeTo(null);
		// 实例化一个 pane
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(null);
		
		JLabel lblNewLabel = new JLabel("学生管理系统");
		lblNewLabel.setForeground(Color.RED);
		lblNewLabel.setFont(new Font("宋体", Font.BOLD, 25));
		lblNewLabel.setBounds(140, 10, 163, 44);
		contentPane.add(lblNewLabel);
		
		JButton addButton = new JButton("添加学生");
		// addActionListener 注册监听器
		addButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				// 设置新窗口可见
				new AddFrame().setVisible(true);
			}
		});
	
		addButton.setFont(new Font("宋体", Font.PLAIN, 18));
		addButton.setBounds(167, 64, 114, 37);
		contentPane.add(addButton);
		
		JButton changeButton = new JButton("修改信息");
		changeButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				// 同上
				new ChangeFrame().setVisible(true);
			}
		});
		changeButton.setFont(new Font("宋体", Font.PLAIN, 18));
		changeButton.setBounds(167, 121, 114, 37);
		contentPane.add(changeButton);
		
		JButton deleteButton = new JButton("删除学生");
		deleteButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				// 同上
				new DeleteFrame().setVisible(true);
			}
		});
		deleteButton.setFont(new Font("宋体", Font.PLAIN, 18));
		deleteButton.setBounds(167, 180, 114, 37);
		contentPane.add(deleteButton);
		
		JButton queryButton = new JButton("查询信息");
		queryButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				// 同上
				new QueryFrame().setVisible(true);
			}
		});
		queryButton.setFont(new Font("宋体", Font.PLAIN, 18));
		queryButton.setBounds(167, 240, 114, 37);
		contentPane.add(queryButton);
	}
}

（2）添加界面

package studentManage;

import java.awt.EventQueue;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.SQLException;

import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;

public class AddFrame extends JFrame {

	private JPanel contentPane;
	private JTextField idField;
	private JTextField nameField;
	private JTextField genderField;
	private JTextField dobField;
	private JTextField batchField;

	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					AddFrame frame = new AddFrame();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public AddFrame() {
		// 和前面类似
		setResizable(false);
		setTitle("添加学生");
		// 这个地方，添加学生只是这个程序的一部分，所以当关闭这部分的时候，程序不直接退出，只是关闭该部分程序
		setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		setBounds(100, 100, 450, 470);
		setLocationRelativeTo(null);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.Y_AXIS));
		
		JPanel panel = new JPanel();
		contentPane.add(panel);
		panel.setLayout(null);
		
		JLabel TitleLabel = new JLabel("请输入新学生的信息：");
		TitleLabel.setFont(new Font("宋体", Font.BOLD, 20));
		TitleLabel.setBounds(71, 34, 220, 45);
		panel.add(TitleLabel);
		
		JLabel idLabel = new JLabel("学号：");
		idLabel.setFont(new Font("宋体", Font.PLAIN, 16));
		idLabel.setBounds(71, 105, 50, 30);
		panel.add(idLabel);
		
		idField = new JTextField();
		idField.setBounds(143, 99, 240, 45);
		panel.add(idField);
		idField.setColumns(10);
		
		JLabel nameLabel = new JLabel("姓名：");
		nameLabel.setFont(new Font("宋体", Font.PLAIN, 16));
		nameLabel.setBounds(71, 160, 50, 30);
		panel.add(nameLabel);
		
		nameField = new JTextField();
		nameField.setColumns(10);
		nameField.setBounds(143, 154, 240, 45);
		panel.add(nameField);
		
		JLabel genderLabel = new JLabel("性别：");
		genderLabel.setFont(new Font("宋体", Font.PLAIN, 16));
		genderLabel.setBounds(71, 215, 50, 30);
		panel.add(genderLabel);
		
		genderField = new JTextField();
		genderField.setColumns(10);
		genderField.setBounds(143, 209, 240, 45);
		panel.add(genderField);
		
		JLabel dobLabel = new JLabel("出生日期：");
		dobLabel.setFont(new Font("宋体", Font.PLAIN, 16));
		dobLabel.setBounds(41, 270, 80, 30);
		panel.add(dobLabel);
		
		dobField = new JTextField();
		dobField.setColumns(10);
		dobField.setBounds(143, 264, 240, 45);
		panel.add(dobField);
		
		JLabel batchLabel = new JLabel("班级：");
		batchLabel.setFont(new Font("宋体", Font.PLAIN, 16));
		batchLabel.setBounds(71, 325, 50, 30);
		panel.add(batchLabel);
		
		batchField = new JTextField();
		batchField.setColumns(10);
		batchField.setBounds(143, 319, 240, 45);
		panel.add(batchField);
		
		JButton addButton = new JButton("添加");
		// 添加鼠标监听事件
		addButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				// 先取出数据
				// getText() 返回字符串类型的
				// Integer.parseInt 数据类型转换
				int id = Integer.parseInt(idField.getText());

				String nameString = nameField.getText();

				String genderString = genderField.getText();

				String dobfieldString = dobField.getText();

				int batch = Integer.parseInt(batchField.getText());
				// 输出一下学生的信息，方便修改
				System.out.println(id + "\t" + nameString + "\t" + genderString + "\t" + dobfieldString + "\t" + batch);
				// SQLHelp 是自己写的一个工具类
				SQLHelp sqlHelp = new SQLHelp();
				try {
					// 调用添加学生信息的方法
					sqlHelp.addStudent(id, nameString, genderString, dobfieldString, batch);
					// 弹出对话框，提示用户添加成功
					JOptionPane.showMessageDialog(AddFrame.this, "添加成功！");
				} catch (SQLException e1) {
					// 这里捕获一下异常，因为学生的学号是唯一的，所以当学号已经存在的时候，提示用户，该学生信息已存在
					// 异常代码为 23000
					if(e1.getSQLState().equals("23000")) {
						JOptionPane.showMessageDialog(AddFrame.this, "添加失败!该学生已存在");
					}
					e1.printStackTrace();
				}

			}
		});
		addButton.setFont(new Font("宋体", Font.PLAIN, 18));
		addButton.setBounds(182, 389, 97, 33);
		panel.add(addButton);
	}
}

（3）删除界面

package studentManage;

import java.awt.EventQueue;
import java.awt.Font;

import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;
import java.awt.event.ActionListener;
import java.sql.SQLException;
import java.awt.event.ActionEvent;

public class DeleteFrame extends JFrame {

	private JPanel contentPane;
	private JTextField idField;
	private JTextField nameField;
	private JTextField genderField;
	private JTextField dobField;
	private JTextField batchField;
	private JTextField searchField;
	

	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					DeleteFrame frame = new DeleteFrame();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public DeleteFrame() {
		setResizable(false);
		setTitle("删除学生");
		setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		setBounds(100, 100, 450, 470);
		setLocationRelativeTo(null);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.Y_AXIS));
		
		JPanel panel = new JPanel();
		contentPane.add(panel);
		panel.setLayout(null);
		
		JLabel lblNewLabel = new JLabel("请输入要删除的学生的学号：");
		lblNewLabel.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel.setBounds(71, 0, 208, 29);
		panel.add(lblNewLabel);
		
		JLabel lblNewLabel_1 = new JLabel("学号：");
		lblNewLabel_1.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1.setBounds(71, 105, 50, 30);
		panel.add(lblNewLabel_1);
		
		idField = new JTextField();
		idField.setEditable(false);
		idField.setBounds(143, 99, 240, 45);
		panel.add(idField);
		idField.setColumns(10);
		
		JLabel lblNewLabel_1_1 = new JLabel("姓名：");
		lblNewLabel_1_1.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1_1.setBounds(71, 160, 50, 30);
		panel.add(lblNewLabel_1_1);
		
		nameField = new JTextField();
		nameField.setColumns(10);
		nameField.setBounds(143, 154, 240, 45);
		panel.add(nameField);
		
		JLabel lblNewLabel_1_1_1 = new JLabel("性别：");
		lblNewLabel_1_1_1.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1_1_1.setBounds(71, 215, 50, 30);
		panel.add(lblNewLabel_1_1_1);
		
		genderField = new JTextField();
		genderField.setColumns(10);
		genderField.setBounds(143, 209, 240, 45);
		panel.add(genderField);
		
		JLabel lblNewLabel_1_1_1_1 = new JLabel("出生日期：");
		lblNewLabel_1_1_1_1.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1_1_1_1.setBounds(41, 270, 80, 30);
		panel.add(lblNewLabel_1_1_1_1);
		
		dobField = new JTextField();
		dobField.setColumns(10);
		dobField.setBounds(143, 264, 240, 45);
		panel.add(dobField);
		
		JLabel lblNewLabel_1_1_1_2 = new JLabel("班级：");
		lblNewLabel_1_1_1_2.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1_1_1_2.setBounds(71, 325, 50, 30);
		panel.add(lblNewLabel_1_1_1_2);
		
		batchField = new JTextField();
		batchField.setColumns(10);
		batchField.setBounds(143, 319, 240, 45);
		panel.add(batchField);
		
		JButton deleteButton = new JButton("删除");
		deleteButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				
				int id = Integer.parseInt(searchField.getText());
				
				try {
					SQLHelp sqlHelp = new SQLHelp();
					
					sqlHelp.deletestudent(id);
					
					JOptionPane.showMessageDialog(DeleteFrame.this, "删除成功！");
				} catch (SQLException e1) {
					JOptionPane.showMessageDialog(DeleteFrame.this, "删除失败");
					e1.printStackTrace();
				}
				
			}
		});
		deleteButton.setFont(new Font("宋体", Font.PLAIN, 18));
		deleteButton.setBounds(182, 389, 97, 33);
		panel.add(deleteButton);
		
		searchField = new JTextField();
		searchField.setBounds(71, 39, 208, 45);
		panel.add(searchField);
		searchField.setColumns(10);
		
		JButton searchButton = new JButton("查找");
		searchButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				
				int id = Integer.parseInt(searchField.getText());
				
				try {
					SQLHelp sqlHelp = new SQLHelp();
					
					Student student = sqlHelp.queryStudent(id);
					
					if(student != null) {
						
						idField.setText(String.valueOf(id));
						nameField.setText(student.getName());
						genderField.setText(student.getGender());
						dobField.setText(student.getDob());
						batchField.setText(String.valueOf(student.getBatch()));
						
					} else {
						JOptionPane.showMessageDialog(DeleteFrame.this, "无此学生");
					}
				} catch (SQLException e) {
					e.printStackTrace();
				}
				
				
			}
		});
		searchButton.setFont(new Font("宋体", Font.PLAIN, 18));
		searchButton.setBounds(289, 42, 97, 39);
		panel.add(searchButton);
	}
}

 （4）修改界面

package studentManage;

import java.awt.EventQueue;
import java.awt.Font;

import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;
import java.awt.event.ActionListener;
import java.sql.SQLException;
import java.awt.event.ActionEvent;

public class ChangeFrame extends JFrame {

	private JPanel contentPane;
	private JTextField idField;
	private JTextField nameField;
	private JTextField genderField;
	private JTextField dobField;
	private JTextField batchField;
	private JTextField searchField;
	

	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					ChangeFrame frame = new ChangeFrame();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public ChangeFrame() {
		setResizable(false);
		setTitle("修改信息");
		setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		setBounds(100, 100, 450, 470);
		setLocationRelativeTo(null);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.Y_AXIS));
		
		JPanel panel = new JPanel();
		contentPane.add(panel);
		panel.setLayout(null);
		
		JLabel lblNewLabel = new JLabel("请输入要修改的学生的学号：");
		lblNewLabel.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel.setBounds(71, 0, 208, 29);
		panel.add(lblNewLabel);
		
		JLabel lblNewLabel_1 = new JLabel("学号：");
		lblNewLabel_1.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1.setBounds(71, 105, 50, 30);
		panel.add(lblNewLabel_1);
		
		idField = new JTextField();
		idField.setEditable(false);
		idField.setBounds(143, 99, 240, 45);
		panel.add(idField);
		idField.setColumns(10);
		
		JLabel lblNewLabel_1_1 = new JLabel("姓名：");
		lblNewLabel_1_1.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1_1.setBounds(71, 160, 50, 30);
		panel.add(lblNewLabel_1_1);
		
		nameField = new JTextField();
		nameField.setColumns(10);
		nameField.setBounds(143, 154, 240, 45);
		panel.add(nameField);
		
		JLabel lblNewLabel_1_1_1 = new JLabel("性别：");
		lblNewLabel_1_1_1.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1_1_1.setBounds(71, 215, 50, 30);
		panel.add(lblNewLabel_1_1_1);
		
		genderField = new JTextField();
		genderField.setColumns(10);
		genderField.setBounds(143, 209, 240, 45);
		panel.add(genderField);
		
		JLabel lblNewLabel_1_1_1_1 = new JLabel("出生日期：");
		lblNewLabel_1_1_1_1.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1_1_1_1.setBounds(41, 270, 80, 30);
		panel.add(lblNewLabel_1_1_1_1);
		
		dobField = new JTextField();
		dobField.setColumns(10);
		dobField.setBounds(143, 264, 240, 45);
		panel.add(dobField);
		
		JLabel lblNewLabel_1_1_1_2 = new JLabel("班级：");
		lblNewLabel_1_1_1_2.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1_1_1_2.setBounds(71, 325, 50, 30);
		panel.add(lblNewLabel_1_1_1_2);
		
		batchField = new JTextField();
		batchField.setColumns(10);
		batchField.setBounds(143, 319, 240, 45);
		panel.add(batchField);
		
		JButton changeButton = new JButton("修改");
		changeButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				
				int id = Integer.parseInt(searchField.getText());
				
				String nameString = nameField.getText();
				
				String gendeString = genderField.getText();
				
				String dobString = dobField.getText();
				
				int batch = Integer.parseInt(batchField.getText());
				
				SQLHelp sqlHelp = new SQLHelp();
				
				try {
					sqlHelp.changeStudent(id, nameString, gendeString, dobString, batch);
					
					JOptionPane.showMessageDialog(ChangeFrame.this, "修改成功！");
				} catch (SQLException e) {
					JOptionPane.showMessageDialog(ChangeFrame.this, "修改失败！");
					e.printStackTrace();
				}
					
			}
		});
		changeButton.setFont(new Font("宋体", Font.PLAIN, 18));
		changeButton.setBounds(182, 389, 97, 33);
		panel.add(changeButton);
		
		searchField = new JTextField();
		searchField.setBounds(71, 39, 208, 45);
		panel.add(searchField);
		searchField.setColumns(10);
		
		JButton searchButton = new JButton("查找");
		searchButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e){
				
				int id = Integer.parseInt(searchField.getText());
				
				try {
					
					SQLHelp sqlHelp = new SQLHelp();
					
					Student student = sqlHelp.queryStudent(id);
					
					if(student != null) {
						
						// id 是直接读入的，所以就不需要从数据库中读出了
						idField.setText(String.valueOf(id));
						nameField.setText(student.getName());
						genderField.setText(student.getGender());
						dobField.setText(student.getDob());
						batchField.setText(String.valueOf(student.getBatch()));
						
					} else {
						JOptionPane.showMessageDialog(ChangeFrame.this, "无此用户");
					}
					
				} catch (SQLException e1) {
					e1.printStackTrace();
				}
				
			}
		});
		searchButton.setFont(new Font("宋体", Font.PLAIN, 18));
		searchButton.setBounds(289, 42, 97, 39);
		panel.add(searchButton);
	}
}

 （5）查找界面

package studentManage;

import java.awt.EventQueue;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.SQLException;

import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;

public class QueryFrame extends JFrame {

	private JPanel contentPane;
	private JTextField idField;
	private JTextField nameField;
	private JTextField genderField;
	private JTextField dobField;
	private JTextField batchField;
	private JTextField searchField;
	

	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					QueryFrame frame = new QueryFrame();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public QueryFrame() {
		setResizable(false);
		setTitle("查询信息");
		setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		setBounds(100, 100, 450, 470);
		setLocationRelativeTo(null);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.Y_AXIS));
		
		JPanel panel = new JPanel();
		contentPane.add(panel);
		panel.setLayout(null);
		
		JLabel lblNewLabel = new JLabel("请输入要查找的学生的学号：");
		lblNewLabel.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel.setBounds(71, 0, 208, 29);
		panel.add(lblNewLabel);
		
		JLabel lblNewLabel_1 = new JLabel("学号：");
		lblNewLabel_1.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1.setBounds(71, 105, 50, 30);
		panel.add(lblNewLabel_1);
		
		idField = new JTextField();
		idField.setEditable(false);
		idField.setBounds(143, 99, 240, 45);
		panel.add(idField);
		idField.setColumns(10);
		
		JLabel lblNewLabel_1_1 = new JLabel("姓名：");
		lblNewLabel_1_1.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1_1.setBounds(71, 160, 50, 30);
		panel.add(lblNewLabel_1_1);
		
		nameField = new JTextField();
		nameField.setColumns(10);
		nameField.setBounds(143, 154, 240, 45);
		panel.add(nameField);
		
		JLabel lblNewLabel_1_1_1 = new JLabel("性别：");
		lblNewLabel_1_1_1.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1_1_1.setBounds(71, 215, 50, 30);
		panel.add(lblNewLabel_1_1_1);
		
		genderField = new JTextField();
		genderField.setColumns(10);
		genderField.setBounds(143, 209, 240, 45);
		panel.add(genderField);
		
		JLabel lblNewLabel_1_1_1_1 = new JLabel("出生日期：");
		lblNewLabel_1_1_1_1.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1_1_1_1.setBounds(41, 270, 80, 30);
		panel.add(lblNewLabel_1_1_1_1);
		
		dobField = new JTextField();
		dobField.setColumns(10);
		dobField.setBounds(143, 264, 240, 45);
		panel.add(dobField);
		
		JLabel lblNewLabel_1_1_1_2 = new JLabel("班级：");
		lblNewLabel_1_1_1_2.setFont(new Font("宋体", Font.PLAIN, 16));
		lblNewLabel_1_1_1_2.setBounds(71, 325, 50, 30);
		panel.add(lblNewLabel_1_1_1_2);
		
		batchField = new JTextField();
		batchField.setColumns(10);
		batchField.setBounds(143, 319, 240, 45);
		panel.add(batchField);
		
		searchField = new JTextField();
		searchField.setBounds(71, 39, 208, 45);
		panel.add(searchField);
		searchField.setColumns(10);
		
		JButton searchButton = new JButton("查找");
		searchButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				
				// 1.读出要查询的学生输入的id
				// 因为学生的学号是唯一的，所以我们根据学号查询后，只会有一条数据
				// 转化一下数据类型
				int id = Integer.parseInt(searchField.getText());
				
				// 2.执行JDBC语句
				try {
					SQLHelp sqlHelp = new SQLHelp();
					
					Student student = sqlHelp.queryStudent(id);
					
					// 3.将查询结果填到文本框中
					// 前提是学生存在
					if(student != null) {
						idField.setText(String.valueOf(id));
						nameField.setText(student.getName());
						genderField.setText(student.getGender());
						dobField.setText(student.getDob());
						batchField.setText(String.valueOf(student.getBatch()));
					} else {
						// 此时学生不存在，提示用户，不存在该学生
						JOptionPane.showMessageDialog(QueryFrame.this, "无此学生");
					}
					
				} catch (SQLException e) {
					e.printStackTrace();
				}
				
			}
		});
		searchButton.setFont(new Font("宋体", Font.PLAIN, 18));
		searchButton.setBounds(289, 42, 97, 39);
		panel.add(searchButton);
	}
}

（6）数据库链接

package studentManage;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public  class SQLHelp {

	public static final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";  
	public static final String DB_URL = "jdbc:mysql://localhost:3306/niit?useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC";

	public static final String username = "root";
	public static final String password = "123456";
	
	private Connection connection = null;
	private PreparedStatement pStatement = null;
	private ResultSet rSet = null;
	
	// 加载驱动
	// 静态初始化块（只执行一次）
	static {
		try {
			Class.forName(JDBC_DRIVER);
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	// 链接数据库
	public void  connectDB() {
		try {
			connection = DriverManager.getConnection(DB_URL,username,password);
			System.out.println("数据库链接成功");
		} catch (SQLException e) {
			System.out.println("数据库链接失败");
			e.printStackTrace();
		}
	}
	
	// 关闭资源
	public void close() {
		if(rSet != null) {
			try {
				rSet.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		
		if(pStatement != null) {
			try {
				pStatement.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		
		if(connection != null) {
			try {
				connection.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
	
	public  void addStudent(int id, String nameString, String genderString, String dobString, int batch) throws SQLException {
		
		// try finally 无论是否抛出异常都将执行 finally 中的语句
		try {
			// 先链接到数据库
			connectDB();
			
			// sql 语句
			// 静态 sql 语句需要进行字符串拼接
			// 动态 sql 语句
			String addsql = "insert into student values(?, ?, ?, ?, ?)";
			
			pStatement = connection.prepareStatement(addsql);
			
			pStatement.setInt(1, id);
			pStatement.setString(2, nameString);
			pStatement.setString(3, genderString);
			pStatement.setString(4, dobString);
			pStatement.setInt(5, batch);
						
			pStatement.executeUpdate();
			
		} finally {
			
			close();
			
		}
		
	}
	
	public void changeStudent(int id, String nameString, String genderString, String dobString, int batch) throws SQLException {
					
		try {
			connectDB();
			
			String changesql = "update student set name = ?, gender = ?, dob = ?, batch = ? where id = ?";
					
			pStatement = connection.prepareStatement(changesql);

			pStatement.setString(1, nameString);
			pStatement.setString(2, genderString);
			pStatement.setString(3, dobString);
			pStatement.setInt(4, batch);
			pStatement.setInt(5, id);
					
			pStatement.executeUpdate();
			
		} finally {
			close();
		}	

	}

	public void deletestudent(int id) throws SQLException {
				
		try {
			
			connectDB();
			
			String deleteString = "select * from student where id = ?";

			pStatement = connection.prepareStatement(deleteString);
			
			pStatement.setInt(1, id);
			
			pStatement.execute();

		} finally {
			close();
		}
		
	}
	
	public Student queryStudent(int id) throws SQLException {
		try {
			connectDB();
			
			String querysql = "select * from student where id = ?";
			pStatement = connection.prepareStatement(querysql);
			pStatement.setInt(1, id);
			// 三种方法执行
			// execute()	都可以使用，返回true或false
			// executeQuery() 专门用于查询，返回结果集
			// executeUpdate() 专门用于删除、更新
			rSet = pStatement.executeQuery();
			
			if(rSet.next()) {
				
				String nameString = rSet.getString(2);
				String genderString = rSet.getString(3);
				String dobString = rSet.getString(4);
				int batchString = rSet.getInt(5);
				
				// 查询到学生信息返回结果集
				return new Student(nameString, genderString, dobString, batchString);
			} else {
				// 没有查询到学生信息，返回null
				return null;
			}

		} finally {
			close();
		}

	}

}

package studentManage;

public class Student {

	private String name;
	private String gender;
	private String dob;
	private int batch;
	
	public Student(String name, String gender, String dob, int batch) {
		this.name = name;
		this.gender = gender;
		this.dob = dob;
		this.batch = batch;
	}
	
	public String getName() {
		return name;
	}
	
	public String getGender() {
		return gender;
	}
	
	public String getDob() {
		return dob;
	}
	
	public int getBatch() {
		return batch;
	}
	
}

package studentManage;


import java.sql.*;

public class JDBC{

    public static void main(String[] args) throws Exception {
        try {
            // 注册 JDBC 驱动
            Class.forName("com.mysql.cj.jdbc.Driver");

            // 打开链接
            Connection conn = DriverManager.getConnection("jdbc:conn-local://localhost:3306/text?useSSL=false&serverTimezone=UTC", "SQ", "109036");

            // 执行查询
            Statement stmt = conn.createStatement();
            String sql = "SELECT id, name, url FROM text";
            ResultSet rs = stmt.executeQuery(sql);

            // 展开结果集数据库
            while (rs.next()) {
                // 通过字段检索
                int id = rs.getInt("id");
                String name = rs.getString("name");
                String url = rs.getString("url");

                // 输出数据
                System.out.print("ID: " + id);
                System.out.print("  NAME " + name);
                System.out.print("  URL: " + url);
                System.out.print("\n");
            }
            // 释放资源
            rs.close();
            stmt.close();
            conn.close();

        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }

    }
}

添加Java驱动包，在官方网站下载mysql-connector-java-8.0.27，根据自己版本下载

3. 数据库链接成功，完成项目的简单操作