?php

class Connection {
  private static $instance;
  private $connection;

  private function __construct()
  {
    $cadena = "host='localhost' port='5432' dbname='newdb' user = 'postgres' password = 'system'";
    $this->connection = pg_connect($cadena) or die ('Error');
    $this->query("SET TIME ZONE -4");
  }



  public static function getInstance(){

    if (!isset(self::$instance))
      self::$instance = new Connection();

    return self::$instance;
  }

  public function query($aQuery){
    //echo "$aQuery<br>";
    return pg_query($this->connection, $aQuery);
  }

}

?>