【数据库】学生管理系统

☞本项目主要练习MySQL数据库和java代码之间的连通☜
☞后续会在本基础上，利用Spring实现WEB端☜
☞梦想进大厂的一只程序猿☜
☞期望毕业前力扣刷够400题☜
☞正在复习数据结构和算法☜
☞博客地址：https://www.huangliangshuai.com/☜

1. 项目架构图

2. 系统分析

2.1. 数据库

2.1.1. 表student

2.2 java端

2.2.1 JBDC

2.2.1.1JDBC连接

package com.situ.student.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ResourceBundle;

public class JDBCUtil {

	private static ResourceBundle rb = ResourceBundle.getBundle("com.situ.student.util.JDBC");
	private static String cLassName = rb.getString("driver");
	private static String url = rb.getString("url");
	private static String user = rb.getString("user");
	private static String password = rb.getString("pass");

	// 1- 加载驱动
	static {
		try {
			Class.forName(cLassName);
		} catch (Exception e) {
			e.getCause();
		}
	}

	// 2- 获得链接
	public static Connection getConnection() throws SQLException {
		return DriverManager.getConnection(url, user, password);
	}

	public static void close(Connection conn, Statement st, ResultSet rs) {
		try {
			if (rs != null) {
				rs.close();
				rs = null;
			}
			if (st != null) {
				st.close();
				st = null;
			}
			if (conn != null) {
				conn.close();
				conn = null;
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

	public static void close(Connection conn, Statement st) {
		close(conn, st, null);
	}

	public static void main(String[] args) throws SQLException {
		// 加载驱动 + 获得链接
		Connection con = JDBCUtil.getConnection();
		System.out.println(con);
		JDBCUtil.close(con, null); // 关闭的是插入的
	}

	private JDBCUtil() {

	}
}

2.2.1.1JDBC配置文件

pass=123456

driver=com.mysql.cj.jdbc.Driver

url=jdbc:mysql://127.0.0.1:3308/demo01?useSSL=false&useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&serverTimezone=Hongkong&allowPublicKeyRetrieval=true

2.2.2 student包

2.2.2.1 Model

package com.situ.student.student.model;

public class StudentModel {
	private String id;
	private String name;
	private String age;
	private String profession;

	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 String getAge() {
		return age;
	}

	public void setAge(String age) {
		this.age = age;
	}

	public String getProfession() {
		return profession;
	}

	public void setProfession(String profession) {
		this.profession = profession;
	}

	@Override
	public String toString() {
		return "StudentModel [id=" + id + ", name=" + name + ", age=" + age + ", profession=" + profession + "]";
	}

}

2.2.2.2 Dao

package com.situ.student.student.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.situ.student.student.model.StudentModel;
import com.situ.student.util.JDBCUtil;

public class StudentDao {
	private Connection connection = null;
	private PreparedStatement ps = null;

	// 增加

	public String insert(StudentModel model) {
		String sql = "insert into student(s_id, name, age, profession) value(?,?,?,?)";
		try {
			connection = JDBCUtil.getConnection(); // 获得链接
			ps = connection.prepareStatement(sql); // 执行SQL
			ps.setString(1, model.getId()); // 填充问号
			ps.setString(2, model.getName());
			ps.setString(3, model.getAge());
			ps.setString(4, model.getProfession());
			int res = ps.executeUpdate(); // 返回改变的记录条数
			return res + "";
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			JDBCUtil.close(connection, ps);
		}
		return -1 + "";
	}

	// 删除
	public String delete(StudentModel model) {
		String sql = "delete from student where  s_id = ?";
		try {
			connection = JDBCUtil.getConnection();
			ps = connection.prepareStatement(sql);
			ps.setString(1, model.getId());
			int res = ps.executeUpdate();
			return res + "";
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			JDBCUtil.close(connection, ps);
		}
		return -1 + "";
	}

	// 修改
	public String update(StudentModel model) {
		String sql = "update student set profession = ? where s_id = ?";
		try {
			connection = JDBCUtil.getConnection();
			ps = connection.prepareStatement(sql);
			ps.setString(1, model.getProfession());
			ps.setString(2, model.getId());
			int res = ps.executeUpdate();
			return res + "";
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			JDBCUtil.close(connection, ps);
		}
		return -1 + "";
	}

	// 查询
	public List<StudentModel> select(StudentModel model) {
		StringBuffer sql = new StringBuffer("select s_id, name, age, profession from student where 1 = 1");
		List<Object> list = new ArrayList<Object>();
		list = where(sql, model);
		List<StudentModel> list2 = new ArrayList<StudentModel>();
		ResultSet set = null;
		try {
			connection = JDBCUtil.getConnection();
			ps = connection.prepareStatement(sql.toString());
			for (int i = 0; i < list.size(); i++) {
				ps.setObject(i + 1, list.get(i));
			}
			set = ps.executeQuery();
			while (set.next()) {
				StudentModel model1 = new StudentModel();
				model1.setId(set.getString("s_id"));
				model1.setName(set.getString("name"));
				model1.setAge(set.getString("age"));
				model1.setProfession(set.getString("profession"));
				list2.add(model1);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			JDBCUtil.close(connection, ps);
		}
		return list2;
	}

	public List<Object> where(StringBuffer sql, StudentModel model) {
		String s_id = model.getId();
		List<Object> list = new ArrayList<Object>();
		if (s_id != null && !s_id.trim().isEmpty()) {
			sql.append(" and s_id=?");
			list.add(s_id);
		}
		String name = model.getName();
		if (name != null && !name.trim().isEmpty()) {
			sql.append(" and name = ?");
			list.add(name);
		}
		String age = model.getAge();
		if (age != null && !age.trim().isEmpty()) {
			sql.append(" and age = ?");
			list.add(age);
		}
		String profession = model.getProfession();
		if (profession != null && !profession.trim().isEmpty()) {
			sql.append(" and profession = ?");
			list.add(profession);
		}
		return list;
	}
}

2.2.2.3 Service

package com.situ.student.student.service;

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

import com.situ.student.student.dao.StudentDao;
import com.situ.student.student.model.StudentModel;

public class StudentService {
	private StudentDao dao = new StudentDao();

	public String insert(StudentModel model) {
		StudentModel model2 = new StudentModel();
		model2.setId(model.getId());
		List<StudentModel> list = new ArrayList<StudentModel>();
		list = dao.select(model);
		if (list == null || list.isEmpty()) {
			dao.insert(model);
			return "插入成功！";
		}
		return "已经存在！";
	}

	public String delete(StudentModel model) {
		return dao.delete(model);
	}

	public String update(StudentModel model) {
		return dao.update(model);

	}

	public List<StudentModel> selectList(StudentModel model) {
		return dao.select(model);
	}

	public StudentModel selcetModel(StudentModel model) {
		StudentModel model2 = new StudentModel();
		model2.setId(model.getId());
		List<StudentModel> list = new ArrayList<StudentModel>();
		list = dao.select(model);
		if (list == null || list.isEmpty()) {
			return null;
		}
		return list.get(0);
	}

}

2.2.2 Test

package com.situ.student.student.studenttest;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import com.situ.student.student.model.StudentModel;
import com.situ.student.student.service.StudentService;

public class StudentTset {
	private Scanner scanner = new Scanner(System.in);
	boolean p = true;
	private StudentService service = new StudentService();

	public static void main(String[] args) {
		StudentTset test = new StudentTset();
		test.start();
	}

	public void start() {
		while (p) {
			System.out.println("1. 添加学生信息");
			System.out.println("2. 按学生姓名查询学生信息");
			System.out.println("3. 修改学生的专业(转专业)");
			System.out.println("4. 按专业查询学生信息");
			System.out.println("5. 查询所有人的信息");
			System.out.println("6. 退出");
			System.out.println("请输入你要");
			String string = scanner.nextLine();
			sart_1(string);
		}
	}

	public void sart_1(String string) {
		if (string.equals("1")) {
			addStudent();
		} else if (string.equals("2")) {
			queryNameStudent();
		} else if (string.equals("3")) {
			setStudentProfessional();
		} else if (string.equals("4")) {
			queryProfessionalStudent();
		} else if (string.equals("5")) {
			querySumInformation();
		} else if (string.equals("6")) {
			p = false;
			System.out.println("已为你退出系统！");
		} else {
			System.out.println("你的输入有误！");
		}
	}

	public void addStudent() {
		StudentModel model = new StudentModel();
		System.out.println("请输入学生的编号：");
		String id = scanner.nextLine();
		System.out.println("请输入学生的名字：");
		String name = scanner.nextLine();
		System.out.println("请输入学生的年龄：");
		String age = scanner.nextLine();
		System.out.println("请输入学生的专业：");
		String profession = scanner.nextLine();
		model.setId(id);
		model.setName(name);
		model.setAge(age);
		model.setProfession(profession);
		System.out.println(service.insert(model));
	}

	// 按名字进行查询
	public void queryNameStudent() {
		System.out.println("请输入你要查询的名字：");
		String name = scanner.nextLine();
		StudentModel model = new StudentModel();
		model.setName(name);
		List<StudentModel> list = new ArrayList<StudentModel>();
		list = service.selectList(model);
		for (int i = 0; i < list.size(); i++) {
			System.out.println(list.get(i));
		}
	}

	public void querySumInformation() {
		StudentModel model = new StudentModel();
		List<StudentModel> list = new ArrayList<StudentModel>();
		list = service.selectList(model);
		for (int i = 0; i < list.size(); i++) {
			System.out.println(list.get(i));
		}
	}

	public void setStudentProfessional() {
		StudentModel model = new StudentModel();
		System.out.println("请输入你要修改的学生编号：");
		String id = scanner.nextLine();
		model.setId(id);
		System.out.println("请输入你要转的专业：");
		String profession = scanner.nextLine();
		model.setProfession(profession);
		service.update(model);
	}

	public void queryProfessionalStudent() {
		System.out.println("请输入你要查询的专业：");
		StudentModel model = new StudentModel();
		String profession = scanner.nextLine();
		model.setProfession(profession);
		List<StudentModel> list = new ArrayList<StudentModel>();
		list = service.selectList(model);
		for (int i = 0; i < list.size(); i++) {
			System.out.println(list.get(i));
		}
	}
}