此行上的一个字段不存在，请检查它们.

One of your fields on this line doesn't exist,check them.

$sql = "SELECT name, kalender_ID FROM kalender WHERE ersteller_ID = ?";

此外，您应该检查$ stmt.

Also, you should be checking for $stmt.

$db = new mysqli("localhost","root","","karmintalender");

 $owner_ID = 1;

 $sql = "SELECT name, kalender_ID FROM kalender WHERE ersteller_ID = ?";
 $stmt = $db->prepare($sql);
 if($stmt){
     $stmt->bind_param("i", $owner_ID);
     $stmt->execute();
     $stmt->bind_results($name, $kalender_ID);

     while ($stmt->fetch()) {
       echo $name . " " . $kalender_ID;
     }
 }