Bu şekilde çözdüm @LetsDuoLimited; @yigitmalik46; @Sinyor_Ridak;

<?php 
include('config.php');

 
$request_uri = $_SERVER['REQUEST_URI'];
$path = parse_url($request_uri, PHP_URL_PATH);

 
$path = str_replace('-sarki-sozleri', '', $path);

 
$path_parts = explode('/', trim($path, '/'));
$baslik_url = end($path_parts);

 
function slugify($text) {
 
    $text = preg_replace('~[^\pL\d]+~u', '-', $text);

 
    $text = iconv('utf-8', 'us-ascii//TRANSLIT', $text);

 
    $text = preg_replace('~[^-\w]+~', '', $text);

 
    $text = trim($text, '-');

 
    $text = preg_replace('~-+~', '-', $text);

 
    $text = strtolower($text);

    if (empty($text)) {
        return 'n-a';
    }

    return $text;
}

 
$wisex = ucwords(str_replace('-', ' ', $baslik_url));
$slugified_wisex = slugify($wisex);

 
$sorgu = $baglanti->prepare("SELECT * FROM sarkilar");
$sorgu->execute();
$sarkilar = $sorgu->fetchAll(PDO::FETCH_ASSOC);

$sonuc = null;
foreach ($sarkilar as $sarki) {
    $db_baslik = $sarki['baslik'];
    $slugified_db_baslik = slugify($db_baslik);
    if ($slugified_db_baslik === $slugified_wisex) {
        $sonuc = $sarki;
        break;
    }
}

 
?>