Sometimes no query result with mysqli

Question

I've wrote this function to read from my MySQL database. This works in most cases, but if it comes to a row with umlauts or characters like "" it returns "0 results".

function leseAntwort($FrageID, $AntwortID){

$sql = "SELECT antwort_text FROM antwort WHERE frage_id=$FrageID AND id=$AntwortID";
$result = connect()->query($sql);

if ($result->num_rows > 0) {
    $antwort = $result->fetch_row();
    connect()->close();
    return $antwort[0];
} else {
    connect()->close();
    return "0 results";
}
}

[UPDATE]

I tried this, but there is no difference between the results.

function leseAntwort($FrageID, $AntwortID){

  $frage=$FrageID;
  $antwort=$AntwortID;
  global $mysqli;
  if ($stmt = $mysqli->prepare("SELECT antwort_text FROM antwort WHERE frage_id=? AND id=?")){
     $stmt->bind_param("ii", $frage, $antwort);
     $stmt->execute();
     $stmt->bind_result($d);
     $stmt->fetch();
     return $d;
     $stmt->close();
     $mysqli->close();
  } else {
    echo "Error";
  }
}

Answer 1

you have an SQL Injection in your SQL Statement. PLZ use Prepared Statements http://php.net/manual/de/mysqli.quickstart.prepared-statements.php After that you can use utf-8 Chars in your Params.