<?php
$pdo = new PDO('mysql:host=localhost;dbname=tutorial', 'la', '123123');

$sql = "SELECT * FROM `kilian` WHERE `id` = 1";
$sql2 = "SELECT * FROM `kilian` WHERE `id` = 2";
foreach ($pdo->query($sql) as $row) {
   $date1 = $row['datum'];
   $weight1 = $row['gewicht'];
}
?>