Некорректно работает запрос в БД

$vaca=new Vote(0, $player, 0,0,0);
$vaca->insert_quantity();

function insert_quantity(){
    Create::connect();
    $sel=mysql_query('SELECT * FROM quantity WHERE id_player='.$this->player);
    $c=mysql_num_rows($sel);
    if($c>0){
        echo 'Вы не можете проголосовать больше 1 раза <br>';
    }else{
        mysql_query('INSERT INTO quantity (id_player) VALUES ('.$this->player.')');
        if(mysql_error()){
            echo mysql_error().'<br>';
        }
        echo 'Ok';
    }
}

if(mysql_error()){
 echo mysql_error().'<br>';
} else {
 echo 'Ok';
}

$player=$_COOKIE['id'];
$player=(integer) $player;
 
$vaca=new Vote(0, $player, 0,0,0);
$vaca->select_quantity();
$count=$vaca->count;
 
echo $count;
echo '<br>';
 
if($count==0){
    $cad=new Vote(0, $player, 0,0,0);
    $cad->insert_quantity();
}

function select_quantity(){
    Create::connect();
    $sel=mysql_query('SELECT * FROM quantity WHERE id_player='.$this->player);
    if(mysql_error()){
        echo mysql_error().'<br>';
    }
    $this->count=mysql_num_rows($sel);;
}
 
function insert_quantity(){
    Create::connect();
    mysql_query('INSERT INTO quantity (id_player) VALUES ('.$this->player.')');
    if(mysql_error()){
        echo mysql_error().'<br>';
    }
    echo 'Ok';  
}

$sel=mysql_query('SELECT * FROM quantity WHERE id_player=1');

mysql_query('INSERT INTO quantity (id_player) VALUES (1)');