<?php
class depertament
{
    public $ID_dept;
    public $nom;
    public $DNI_director;
    public $data_ingres_director;

    public function mostra()
    {
        echo $this->ID_dept . " ".$this->nom." [" . $this->DNI_director . "] ".$this->$data_ingres_director."\n";
    }
}

$db_host="localhost"; $db_nom="empresa"; $db_user="root"; $db_pass="";
$conn = mysqli_connect($db_host, $db_user, $db_pass, $db_nom) ;

$result = mysqli_query($conn, "SELECT * FROM departament ");

try {
    $manager = new MongoDB\Driver\Manager("mongodb://localhost:27017");

    while ($row = mysqli_fetch_array($result))  {
        $e = new depertament();
        $e->ID_dept = $row["ID_dept"];
        $e->nom = $row["nom"];
        $e->DNI_director = $row["DNI_director"];
        $e->data_ingres_director = $row["data_ingres_director"];

        $bulk = new MongoDB\Driver\BulkWrite;

        $bulk->insert($e);

        $res = $manager->executeBulkWrite('test.departament_sql', $bulk);
        var_dump($res);echo "<br>";
        var_dump($e);echo "<br>";
    }

    mysqli_free_result($result);
    mysqli_close($conn);

}catch(Exception $e) {
   echo "EXCEPTION: ".$e->getMessage(), "\n";
   exit;
}
?>