üye kontrol hatası

function girisyapilmismi()
{
    
    
            $kullanici_adi=@$_COOKIE['uye_kullanici_adi'];
            $sifre=@$_COOKIE['uye_sifre'];
            $uye_id=@$_COOKIE['uye_id'];
            
            $giriskontrol=mysql_query("Select * From uyeler Where (kullaniciAdi='{$kullanici_adi}' || eposta='{$kullanici_adi}' ) and sifre='{$sifre}' and id='{$uye_id}' ") or logal(mysql_error());
            $uyesayisi=mysql_num_rows($giriskontrol);
            if($uyesayisi=="1")
            {
                $bil=mysql_fetch_object($giriskontrol);
                if($bil->aktif=="1"){
                $_SESSION['girisID']=$uye_id;
                    return true;
                }else{
                    return false;
                }
        
            }else if($uyesayisi>"1")
            {
            
                return false;
            }else
            {
            $uyeid=@$_SESSION['girisID'];
            $giriskontrol=mysql_query("Select id From uyeler Where id='{$uyeid}' ") or logal(mysql_error());
            $uyesayisi=mysql_num_rows($giriskontrol);
            if($uyesayisi=="1")
            {
                return true;
            }else{
                return false;
            }}
}

try{
    $db = new PDO("mysql:host=LOCALHOST;dbname=DBNAME;charset=utf8","KULLANICIADI","ŞİFRE");
}catch (PDOException $h) {
$hata = $h->getMessage();
    echo "<b>HATA:</b> ".$hata;
}

function girisyapilmismi()
{
global $db;
$kullanici_adi=@$_COOKIE['uye_kullanici_adi'];
$sifre=@$_COOKIE['uye_sifre'];
$uye_id=@$_COOKIE['uye_id'];
    $sql = $db->prepare("Select * From uyeler Where (kullaniciAdi='{$kullanici_adi}' || eposta='{$kullanici_adi}') and sifre='{$sifre}' and id='{$uye_id}' and aktif=1");
    $sql->execute();
    $rowCount = $sql->rowCount();
    if($rowCount==1){            
        $_SESSION['girisID']=$uye_id;
        return true;
    }elseif($rowCount>1){
        return false;
    }else{
        $uyeid=@$_SESSION['girisID'];
        $sql = $db->prepare("Select id From uyeler Where id='{$uyeid}'");
        $sql->execute();
        return $sql->rowCount()==1 ? true:false;                
    }            
}