if(isset($_GET['yil'], $_GET['ay'])){
$sorgu = "SELECT adi as titlem FROM tablo WHERE YEAR(tarih)= '{$_GET['yil']}' AND MONTH(tarih)= '{$_GET['ay']}' ";
}
elseif(isset($_GET['yil'])){
$sorgu = "SELECT MONTH(tarih) as titlem FROM tablo WHERE YEAR(tarih)= '{$_GET['yil']}' GROUP BY titlem";
}
else{
$sorgu = "SELECT YEAR(tarih) as titlem FROM tablo WHERE tarih GROUP BY titlem";
}

$db = $genel->baglan;
$query = $db->query($sorgu, PDO::FETCH_ASSOC);
if ( $query ){

foreach($query as $veri){
echo $veri['titlem'].'<br />';
}
}