<?php

  class Database extends PDO {

    private $host = '127.0.0.1';
    private $db   = 'database_name';
    private $user = 'anything_but_root';
    private $pass = 'anything_but_password';
    private $charset = 'utf8mb4';

    public function __construct() {
      $dsn = "mysql:host=$this->host;dbname=$this->db;charset=$this->charset";
      $opt = [
          PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
          PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_OBJ,
          PDO::ATTR_EMULATE_PREPARES   => false
      ];

      try {
        $this->$db = new PDO($dsn, $this->user, $this->pass, $opt);
      }
        catch(PDOException $e) {
        $this->error = $e->getMessage(); # For development ONLY!
        /* return FALSE; */ # uncomment in production.
      }
    }

    public function close_conn() {
        $this->pdo = null; /* Set the PDO object to null to close the connection */
    }
  }