使用preparestatement实现查询登陆功能 230223

用户输入帐号与密码后验证是否成功

成功与失败就显示相关信息

import com.sun.org.apache.xpath.internal.operations.Bool;

import java.sql.*;
import java.util.Scanner;

public class Test {
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        // 驱动
        Class.forName("com.mysql.jdbc.Driver");

        // 连接
        String url = "jdbc:mysql://localhost:3306/heighschool";
        String user = "root";
        String password = "root123";
        Connection connection = DriverManager.getConnection(url, user, password);

        // 接收数据
        Scanner scanner = new Scanner(System.in);

        System.out.println("请输入用户名：");
        String username = scanner.nextLine();
        System.out.println("请输入密码：");
        String pwd = scanner.nextLine();

        // sql
        String sql = "SELECT * FROM USER WHERE NAME = ? AND PASSWORD = ?";
        System.out.println(sql);
        // statement
        PreparedStatement preparedStatement = connection.prepareStatement(sql);
        preparedStatement.setObject(1, username);
        preparedStatement.setObject(2, pwd);
        // resultset
        ResultSet resultSet = preparedStatement.executeQuery();

        // if
        if (resultSet.next()) {
            System.out.println("登陆成功");
        } else {
            System.out.println("登陆失败");
        }

    }
}