Problem with select statement using OOP in PHP

Well i am trying to get the number of rows that match the criteria in the table. Here is my code. It shows nothing. someone please help me asap. Well i modified the code that i made for fetching data. I dunno where i went wrong. I am amateur to OOP .


<?php

$conn=mysql_connect('localhost','root','') or die("Could not connect to server.");
$db=mysql_select_db("career",$conn) or die("Database recess not found.");

class Database
{
    public function selects($table, $rows, $where)
    {
        $q = 'SELECT '.$rows.' FROM '.$table;
        if($where != NULL)
            $q .= ' WHERE '.$where;
        

        $query = @mysql_query($q);
        $counts = @mysql_num_rows($query);
        return $counts;
        
    }
    public function getResult()
    {
        return $this->result;
    }
} 

    $show = new Database();
        $show->selects("jobs","id","`city` = 'Nepalgunj'");
    $show->getResult();

?>