MySQL과 Java를 사용하여 간단한 온라인 여행 예약 시스템을 개발하는 방법

CREATE TABLE products (
    id INT PRIMARY KEY AUTO_INCREMENT,
    name VARCHAR(50) NOT NULL,
    description VARCHAR(255),
    price DECIMAL(8, 2) NOT NULL
);

CREATE TABLE users (
    id INT PRIMARY KEY AUTO_INCREMENT,
    username VARCHAR(50) NOT NULL,
    password VARCHAR(50) NOT NULL,
    email VARCHAR(50) NOT NULL
);

CREATE TABLE orders (
    id INT PRIMARY KEY AUTO_INCREMENT,
    product_id INT NOT NULL,
    user_id INT NOT NULL,
    quantity INT NOT NULL,
    total_price DECIMAL(8, 2) NOT NULL,
    order_date DATE NOT NULL,
    FOREIGN KEY (product_id) REFERENCES products(id),
    FOREIGN KEY (user_id) REFERENCES users(id)
);

import java.sql.*;

public class TravelBookingSystem {
    private static final String JDBC_URL = "jdbc:mysql://localhost/travel_booking_system";
    private static final String USERNAME = "root";
    private static final String PASSWORD = "password";

    public static void main(String[] args) {
        Connection connection = null;
        Statement statement = null;
        ResultSet resultSet = null;

        try {
            connection = DriverManager.getConnection(JDBC_URL, USERNAME, PASSWORD);
            statement = connection.createStatement();
            resultSet = statement.executeQuery("SELECT * FROM products");

            while (resultSet.next()) {
                int id = resultSet.getInt("id");
                String name = resultSet.getString("name");
                String description = resultSet.getString("description");
                double price = resultSet.getDouble("price");

                System.out.println("Product ID: " + id);
                System.out.println("Name: " + name);
                System.out.println("Description: " + description);
                System.out.println("Price: $" + price);
                System.out.println();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (resultSet != null) resultSet.close();
                if (statement != null) statement.close();
                if (connection != null) connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

import java.sql.*;

public class TravelBookingSystem {
    // ...

    public static void registerUser(String username, String password, String email) {
        Connection connection = null;
        PreparedStatement preparedStatement = null;

        try {
            connection = DriverManager.getConnection(JDBC_URL, USERNAME, PASSWORD);
            preparedStatement = connection.prepareStatement("INSERT INTO users (username, password, email) VALUES (?, ?, ?)");
            preparedStatement.setString(1, username);
            preparedStatement.setString(2, password);
            preparedStatement.setString(3, email);

            preparedStatement.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (preparedStatement != null) preparedStatement.close();
                if (connection != null) connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void createOrder(int productId, int userId, int quantity) {
        Connection connection = null;
        PreparedStatement preparedStatement = null;

        try {
            connection = DriverManager.getConnection(JDBC_URL, USERNAME, PASSWORD);
            preparedStatement = connection.prepareStatement("INSERT INTO orders (product_id, user_id, quantity, order_date) VALUES (?, ?, ?, CURDATE())");
            preparedStatement.setInt(1, productId);
            preparedStatement.setInt(2, userId);
            preparedStatement.setInt(3, quantity);

            preparedStatement.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (preparedStatement != null) preparedStatement.close();
                if (connection != null) connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}