Hvordan laver man num_rows på en table ...

<?php
                    $forum_cat  = "SELECT * FROM `web_forum`";
                   
                    if($forum_cat_resultater = $mysqli->query($forum_cat)){
                        while($forum_cat = $forum_cat_resultater->fetch_object()){
                            if($forum_cat_resultater->num_rows >= 1){   
                            $count_rows = mysqli_num_rows($forum_cat_resultater);
                                echo "<li>$forum_cat->id_cat. <a href=\"forum.php?cat={$forum_cat->id_cat}\">$forum_cat->forum
                                <span class=\"count\">$count_rows HER</span></a></li><br>";
                            }
                        }
                        $forum_cat_resultater->close();
                    }

                echo "<li>Ny <a href=\"oprettraad.php\">Opret ny tråd</a></li></ul>";
                echo "</div>"; // Web forumet
                echo "<div id=\"web-forum-indhold\">";
                echo "<ul>";
                    $forum_cat_forum_id  = "SELECT * FROM `web_traade` WHERE `forum_id` = $_GET[cat]";   
                    if($forum_cat_forum_id_resultater = $mysqli->query($forum_cat_forum_id)){
                        while($forum_id = $forum_cat_forum_id_resultater->fetch_object()){
                            if($forum_cat_forum_id_resultater->num_rows >= 1){       
                                echo "<li>$forum_id->id. <a href=\"forum.php?cat={$forum_id->forum_id}&thread={$forum_id->id}\">
                                ".ucfirst($forum_id->traad_navn)."</a></li>";
                            }
                        }
                   
                        $forum_cat_forum_id_resultater->close();
                    }
                echo "</ul>";
                echo "</div>";   
                if($_GET['cat'] && $_GET['thread']){
                echo "<div id=\"thread\">";
                    $se_traad  = "SELECT * FROM `web_traade` WHERE `id` = $_GET[thread]";
                       
                    if($se_traad_resultater = $mysqli->query($se_traad)){
                        while($se_traad = $se_traad_resultater->fetch_object()){
                            if($se_traad_resultater->num_rows >= 1){   
                                echo "$se_traad->traad_navn <br>";   
                                echo "$se_traad->traad_svar";
                            }
                        }
                        $se_traad_resultater->close();
                    }
                    echo "</div>";
                }
?>

$count_traade  = "SELECT `forum_id` COUNT(*) AS `counts` FROM `web_traade` GROUP BY `forum_id`";
                       
                    if($count_traade_resultater = $mysqli->query($count_traade)){
                        while($count_traade_row = $count_traade_resultater->fetch_object()){
                            $count = $count_traade_row->counts;
                        }
                    }

CREATE TABLE IF NOT EXISTS `web_forum` (
  `id_cat` int(11) NOT NULL AUTO_INCREMENT,
  `forum` varchar(150) NOT NULL,
  PRIMARY KEY (`id_cat`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=11 ;

--
-- Dumping data for table `web_forum`
--

INSERT INTO `web_forum` (`id_cat`, `forum`) VALUES
(1, 'Php, MySQL'),
(2, 'Ajax, Jquery, Javascript'),
(3, 'Html, D-HTML, CSS'),
(4, 'S&oslash;gemaskiner / SEO '),
(5, 'ASP,  ASP.NET'),
(6, 'Perl/CGI'),
(7, 'C#'),
(8, 'Generelt'),
(9, 'Alt om Web-integrator'),
(10, 'Job som Web-integrator ?');



CREATE TABLE IF NOT EXISTS `web_svar` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `svar_id` int(11) NOT NULL,
  `forum_svar` varchar(150) NOT NULL,
  `svar_navn` varchar(150) NOT NULL,
  `svar_email` varchar(150) NOT NULL,
  `svar` longtext NOT NULL,
  `svar_tid` varchar(150) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

CREATE TABLE IF NOT EXISTS `web_traade` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `forum_id` int(11) NOT NULL,
  `traad_navn` varchar(150) NOT NULL,
  `traad_svar` longtext NOT NULL,
  `traad_tid` varchar(150) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=9 ;

--
-- Dumping data for table `web_traade`
--

INSERT INTO `web_traade` (`id`, `forum_id`, `traad_navn`, `traad_svar`, `traad_tid`) VALUES
(1, 10, 'Job', 'Jobnet', ''),
(2, 10, 'job igen', 'jobbe', ''),
(3, 2, 'hjælp', 'Hej ', ''),
(4, 2, 'kn', 'okokok', ''),
(5, 2, '5t5t', '4t4t', ''),
(6, 2, 'gege', 'egeg', ''),
(7, 6, '5t5t', '5t5t5y45y', ''),
(8, 8, 'hej hjælp', 'hehehgeg', '');

CREATE TABLE `web_categories` (
  `cat_id` int(11) NOT NULL AUTO_INCREMENT,
  `cat_name` varchar(150) NOT NULL,
  `cat_description` varchar(150) NOT NULL,
  PRIMARY KEY (`cat_id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=11 ;

--
-- Data dump for tabellen `web_categories`
--

INSERT INTO `web_categories` VALUES(1, 'Php, MySQL', '');
INSERT INTO `web_categories` VALUES(2, 'Ajax, Jquery, Javascript', '');
INSERT INTO `web_categories` VALUES(3, 'Html, D-HTML, CSS', '');
INSERT INTO `web_categories` VALUES(4, 'S&oslash;gemaskiner / SEO ', '');
INSERT INTO `web_categories` VALUES(5, 'ASP,  ASP.NET', '');
INSERT INTO `web_categories` VALUES(6, 'Perl/CGI', '');
INSERT INTO `web_categories` VALUES(7, 'C#', '');
INSERT INTO `web_categories` VALUES(8, 'Generelt', '');
INSERT INTO `web_categories` VALUES(9, 'Alt om Web-integrator', '');
INSERT INTO `web_categories` VALUES(10, 'Job som Web-integrator ?', '');

-- --------------------------------------------------------

--
-- Struktur-dump for tabellen `web_posts`
--

CREATE TABLE `web_posts` (
  `post_id` int(11) NOT NULL AUTO_INCREMENT,
  `post_content` longtext NOT NULL,
  `post_date` datetime NOT NULL,
  `post_topic` int(11) NOT NULL,
  `post_by` int(11) NOT NULL,
  PRIMARY KEY (`post_id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

--
-- Data dump for tabellen `web_posts`
--


-- --------------------------------------------------------

--
-- Struktur-dump for tabellen `web_topic`
--

CREATE TABLE `web_topic` (
  `topic_id` int(11) NOT NULL AUTO_INCREMENT,
  `topic_subject` varchar(255) NOT NULL,
  `topic_content` longtext NOT NULL,
  `topic_date` datetime NOT NULL,
  `topic_cat` int(11) NOT NULL,
  `topic_by` varchar(100) NOT NULL,
  PRIMARY KEY (`topic_id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=4 ;

--
-- Data dump for tabellen `web_topic`
--

INSERT INTO `web_topic` VALUES(1, 'efe', 'efe', '0000-00-00 00:00:00', 1, 'kasbas91');
INSERT INTO `web_topic` VALUES(2, 'yjyj', 'yjyj', '0000-00-00 00:00:00', 1, 'kasbas91');

$katagorier_query  = "SELECT * FROM `web_categories`";
if($katagorier_resultater = $mysqli->query($katagorier_query)){
    while($katagorier = $katagorier_resultater->fetch_object()){
        if($katagorier_resultater->num_rows >= 1){   
        $count_rows = mysqli_num_rows($forum_cat_resultater);
            echo "<li>{$katagorier->cat_id}. <a href=\"forum.php?cat={$katagorier->cat_id}\">{$katagorier->cat_name} <br>
            <span class='katagorier_description'>$katagorier->cat_description</span></a></li><br>";
        }
    }
    $katagorier_resultater->close();
}

// HER BLIVER MINE KATAGORIER VIST
$katagorier_query  = "SELECT * FROM `web_categories`";
if($katagorier_resultater = $mysqli->query($katagorier_query)){
    while($katagorier = $katagorier_resultater->fetch_object()){
        if($katagorier_resultater->num_rows >= 1){   
            $count_query = "SELECT COUNT() FROM `web_categories` WHERE `cat_id` = $katagorier->cat_id";
            echo "<li>{$katagorier->cat_id}. <a href=\"forum.php?cat={$katagorier->cat_id}\">{$katagorier->cat_name} <br>
            <span class='katagorier_description'>$katagorier->cat_description</span></a></li><br>";
        }
    }
    $katagorier_resultater->close();
}

$katagorier_query_select  = "SELECT `cat_id` FROM `web_categories`";
if($katagorier_resultater = $mysqli->query($katagorier_query_select)){
    while($katagorier_select = $katagorier_resultater->fetch_object()){

    $count_rows = "SELECT COUNT(`topic_cat`) AS `count` FROM `web_topic` WHERE `topic_cat` = $katagorier_select->cat_id GROUP BY `topic_cat`";
        if($count_rows_resultater = $mysqli->query($count_rows)){
            while($count_row = $count_rows_resultater->fetch_row()){
                $select_count = $count_row->count;
            }
        }
    }
}

// HER BLIVER MINE KATAGORIER VIST
                    $katagorier_query  = "SELECT * FROM `web_categories`";
                    if($katagorier_resultater = $mysqli->query($katagorier_query)){
                        while($katagorier = $katagorier_resultater->fetch_object()){
                            if($katagorier_resultater->num_rows >= 1){   
                            echo "<li>{$katagorier->cat_id}. <a href=\"forum.php?cat={$katagorier->cat_id}\">{$katagorier->cat_name} <br>
                                <span class='katagorier_description'>$katagorier->cat_description</span></a>
                                <span class=\"count\" id=\"$select_id\">$select_count</span></li><br>";
                            }
                        }
                        $katagorier_resultater->close();
                    }

$katagorier_query  = "SELECT * FROM `web_categories`";
if($katagorier_resultater = $mysqli->query($katagorier_query)){
    while($katagorier = $katagorier_resultater->fetch_object()){
        if($katagorier_resultater->num_rows >= 1){
            $count_rows = "SELECT COUNT(`topic_cat`) AS `count` FROM `web_topic` WHERE `topic_cat` = $katagorier->cat_id";
            if($count_rows_resultater = $mysqli->query($count_rows)){
                while($count_row = $count_rows_resultater->fetch_row()){
                    $select_count = $count_row[0];
                }
            }
        }
        echo "<li>
        Der er {$select_count} indlæg. <a href=\"forum.php?cat={$katagorier->cat_id}\">
        {$katagorier->cat_name} <br><span class='katagorier_description'>{$katagorier->cat_description}</span></a></li><br>";
    }   
    $katagorier_resultater->close();
}