package javasql;

import java.sql.*;

public class JavaSQL {

    private static String url = "jdbc:mysql://localhost:3306/javasql";
    private static String driver = "com.mysql.jdbc.Driver";

    private static Connection cnx = null;

    protected static void conectar() {
        if (cnx == null) {
            System.out.println("Conectando...");
            try {
                Class.forName(driver);
                cnx = DriverManager.getConnection(url, "root", "");
            } catch (SQLException e) {
                System.out.println(e.getMessage() + ". Error de Conexion CE02");
            } catch (ClassNotFoundException e) {
                System.out.println(e.getMessage() + ". Error de Conexion CE01");
            } finally {
                if (cnx != null) System.out.println("Conectado con exito!!");
            }
        }
    }

    protected static void desconectar() {
        if (cnx != null) {
            System.out.println("Desconectando...");

            try {
                cnx.close();
                cnx = null;
            } catch (SQLException e) {
                System.out.println(e.getMessage() + ". Error de Desconexion DC01");
            } finally {
                if (cnx == null) System.out.println("Desconectado con exito!!");
            }
        }
    }

    public static void main(String[] args) {
        conectar();
    }

}

create database javasql;

use javasql;

create table usuario (
    id int not null auto_increment primary key,
    username varchar(125) unique,
    password varchar(125),
    created_at datetime
);