<?php
require 'db_config.php';

if(isset($_GET["id"]))
{
    $id  = $_GET["id"];
    $sql = "SELECT `groupid`, `groupname`, `date_started`, `Anmerkung` FROM `gruppe` WHERE groupid = " . $id . ";";
}
else
{
    $sql = "SELECT `groupid`, `groupname`, `date_started`, `Anmerkung` FROM `gruppe`;";
}

$result = $mysqli->query($sql);
if ($result != null)
{
    while($row = $result->fetch_assoc()){
        $json[] = $row;
    }

    $data['data'] = $json;
    $result =  mysqli_query($mysqli,$sql);
    echo json_encode($data);
}
else
    echo "<br><br>keine Daten empfangen!<br><br>";
?>