java学习day24-JDBC-学生信息管理系统

学生信息管理-控制台输入

执行SQL脚本

-- 1、创建数据库jt_db数据库(如果不存在才创建)
create database if not exists jt_db charset utf8;
use jt_db; -- 选择jt_db数据库
-- 2、在 jt_db 库中创建 stu 表(学生表)
drop table if exists stu;
create table stu(
	id int,
	name varchar(50),
	gender char(2),
	addr varchar(50),
	score double
);
-- 3、往 stu 表中, 插入记录
insert into stu values(1001,'张三','男', '北京', 86);

封装工具类

package com.tedu;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
/** JDBC工具类 */
public class JdbcUtil {
	/**
	 * 获取数据库连接对象并返回
	 * @return Connection对象
	 * @throws Exception 
	 */
	public static Connection getConn() throws Exception{
		//1.注册驱动
		Class.forName( "com.mysql.jdbc.Driver" );
		//2.获取连接
		Connection conn = DriverManager.getConnection(
				"jdbc:mysql:///jt_db?characterEncoding=utf-8", 
				"root", 
				"1234");
		return conn;
	}
	
	/**
	 * 释放JDBC程序中的资源
	 * @param conn 连接对象
	 * @param stat 传输器对象
	 * @param rs 结果集对象
	 */
	public static void close(Connection conn, 
			Statement stat, ResultSet rs){
		if(rs != null){
			try {
				rs.close();
			} catch (SQLException e) {
				e.printStackTrace();
			} finally{
				rs = null;
			}
		}
		if(stat != null){
			try {
				stat.close();
			} catch (SQLException e) {
				e.printStackTrace();
			} finally{
				stat = null;
			}
		}
		if(conn != null){
			try {
				conn.close();
			} catch (SQLException e) {
				e.printStackTrace();
			} finally{
				conn = null;
			}
		}
	}
}

测试代码

package com.tedu;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.Scanner;

import com.tedu.util.JdbcUtil;

/**
 * 学生信息管理系统
 * 运行程序,根据选项,可以对学生信息进行增删改查操作。
 */
public class StudentManager {
	private static Scanner sc = new Scanner(System.in);
	
	public static void main(String[] args) {
		while (true) {
			//1.提示选择操作选项
			System.out.print("a：查询学生信息  ");
			System.out.print("b：添加学生信息  ");
			System.out.print("c：修改学生信息  ");
			System.out.println("d：删除学生信息");
			System.out.print("请输入操作，abcd任选一项：");
			String opt = sc.next();
			//2.根据选项执行不同操作
			if( "a".equalsIgnoreCase( opt ) ){
				findAll(); //查询学生信息
			}else if( "b".equalsIgnoreCase( opt ) ){
				addStu(); //添加学生信息
			}else if( "c".equalsIgnoreCase( opt ) ){
				updateStu(); //修改学生信息
			}else if( "d".equalsIgnoreCase( opt ) ){
				deleteStu(); //删除学生信息
			}else{
				System.out.println("输入错误，请重新输入！");
			}
		}
	}
	
	/** a. 查询所有学生信息 */
	private static void findAll() {
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		try {
			conn = JdbcUtil.getConn();
			String sql = "select * from stu";
			ps = conn.prepareStatement(sql);
			rs = ps.executeQuery();
			while(rs.next()){
				int id = rs.getInt("id");
				String name = rs.getString("name");
				String gender = rs.getString("gender");
				String addr = rs.getString("addr");
				double score = rs.getDouble("score");
				System.out.println( id+"，"+name+"，"+gender
						+"，"+addr+"，"+score );
			}
			System.out.println("------------------------------------------------------------------------------");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	/** b. 添加学生信息 */
	private static void addStu() {
		System.out.println("请输入要添加的学生编号、姓名、性别、地址、成绩(使用空格分隔)：");
		int id = sc.nextInt();
		String name = sc.next();
		String gender = sc.next();
		String addr = sc.next();
		double score = sc.nextDouble();
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		try {
			conn = JdbcUtil.getConn();
			String sql = "insert into stu values(?,?,?,?,?)";
			ps = conn.prepareStatement(sql);
			ps.setInt(1, id);
			ps.setString(2, name);
			ps.setString(3, gender);
			ps.setString(4, addr);
			ps.setDouble(5, score);
			int rows = ps.executeUpdate();
			if (rows > 0) {
				System.out.println("添加成功!");
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	/** c. 根据id修改学生信息 */
	private static void updateStu() {
		System.out.println("请输入要修改的学生编号、姓名、性别、地址、成绩(使用空格分隔)：");
		int id = sc.nextInt();
		String name = sc.next();
		String gender = sc.next();
		String addr = sc.next();
		double score = sc.nextDouble();
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		try {
			conn = JdbcUtil.getConn();
			String sql = "update stu set name=?,gender=?"
					+ ",addr=?,score=? where id=?";
			ps = conn.prepareStatement(sql);
			ps.setString(1, name);
			ps.setString(2, gender);
			ps.setString(3, addr);
			ps.setDouble(4, score);
			ps.setInt(5, id);
			int rows = ps.executeUpdate();
			if (rows > 0) {
				System.out.println("修改成功!");
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	/** d. 根据id删除学生信息 */
	private static void deleteStu() {
		System.out.println("请输入要删除的学生编号：");
		int id = sc.nextInt();
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		try {
			conn = JdbcUtil.getConn();
			String sql = "delete from stu where id=?";
			ps = conn.prepareStatement(sql);
			ps.setInt(1, id);
			int rows = ps.executeUpdate();
			if (rows > 0) {
				System.out.println("删除成功!");
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}