package db;

import java.sql.Connection;
import java.sql.DriverManager;

public class DBConnection {
    public static Connection getInstance() {
        String username = "root";
        String password = "1234";
        String url = "jdbc:mariadb://localhost:3306/cosdb";

        // 프로토콜이 적용된 소켓
        try {
            Connection conn = DriverManager.getConnection(url, username, password);
            System.out.println("?!!");
            return conn;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

import db.DBConnection;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class BankApp {
    public static void main(String[] args) {
        Connection conn = DBConnection.getInstance();
        try {
            String insert = "insert into account_tb(password, balance, created_at) values(?, ?, now())";
            String delete = "delete from account_tb where number = ?";
            String update = "update account_tb set balance = balance + ? where number = ?";

            PreparedStatement pstmt = conn.prepareStatement(update);
            pstmt.setInt(1, 5000); // 1부터 시작함
            pstmt.setInt(2, 1);

            //pstmt.setInt(2, 1); // false
            int num = pstmt.executeUpdate();
            System.out.println(num);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}