XAMPP - how to expand a category list imported from MySQL

I have imported a set of different values from two different tables in phpMyAdmin, one from Category table (where cat_id is a PK) and another from Item table; where (cat_id is a FK).

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

$que = "SELECT * FROM category";
$run = mysql_query($que);
$j = 0;
while($row = mysql_fetch_array($run))
{
    $cat_idd[$j] = $row['cat_id'];
    $cat_namee[$j] = $row['cat_name'];
    $j++;
}
for($i = 0;  $i < count($cat_idd);  $i++)
{
    $que2 = "SELECT * FROM item WHERE cat_id = '$cat_idd[$i]' ";
    $result = mysql_query($que2);
    $run = mysql_num_rows($result);
    echo "<a href=''>".$cat_namee[$i]."(".$run.")</a><br>";
}
?>

Here is what I have so far:

Now how do I expand it? or for example, how do I show the two items that are stored in the category named Clothing on the same page or next? Since this code only helps me to view the number of items stored inside the database,

Here is my form:

    <form name = "view" method = "POST" action ="cart.php">
      <table align = 'center' width = '100%' border = '4'>
      <tr bgcolor = 'yellow'>
      <td colspan = '20' align = 'center'><h2> Viewing all the Products </td>
</tr>
      <tr align = 'center'>
      <th>Item ID</th>
      <th>Name</th>
      <th>Price</th>
      <th>Select</th>
      </tr>

      <tr  class = "odd">


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

        $que = "SELECT * FROM category";
        $run = mysql_query($que);
        $j = 0;
      while($row = mysql_fetch_array($run))
       {
         $cat_idd[$j] = $row['cat_id'];
         $cat_namee[$j] = $row['cat_name'];
         $j++;
       }

I thought of using an array function to store the value inside a category i.e Clothing(2) => 2.

       function array_insert(&$array, $position, $insert)
       {
         if (is_int($position)) {
          array_splice($array, $position, 0, $insert);
       } else {
          $pos   = array_search($position, array_keys($array));
          $array = array_merge(
             array_slice($array, 0, $pos),
             $insert,
            array_slice($array, $pos)
        );
       }
       }

      $arr = array();
      $arr[] = 2;


      for($i = 0;  $i < count($cat_idd);  $i++)
      {
       $que2 =  "SELECT * FROM item WHERE cat_id = '$cat_idd[$i]'";
       $result = mysql_query($que2);
       $run = mysql_num_rows($result);
       echo "<a href=''>".$cat_namee[$i]."(".$run.")</a><br>";
     array_insert($arr, 0, "$run");
     // echo $arr[0];
      }
        $que2 = "SELECT * FROM item WHERE cat_id = '1'";      //instead of using '1' i wish to use the one user clicks on!
        $res2 = mysql_query($que2);
       while($row = mysql_fetch_array($res2))
        {
          $i_id = $row['item_id'];
          $i_namee = $row['item_name'];
          $i_price = $row['item_price'];


       ?>
       <td><?php echo $i_id; ?></td>
       <td><?php echo $i_namee; ?></td>
       <td><?php echo $i_price; ?></td>
       <td><input type="checkbox" name="addcart" value="<?php echo $item; ?>" onClick="return KeepCount()" />Tick</td>
</tr>
       <?php }  ?>    
       <br><br>
       </table>
       <input type = "hidden" name = "check">
       <button type=  "submit" onclick = "location.href = 'cart.php';" id = "cart" style="float:right; margin-top: 30px; margin-right: 10px;">Add to Cart</button>

The above image is the result what I want, this one is specific for Clothing(2) only. I want it to change as the user clicks on something else for example, Shoes(1).