php Multiple looping problem

Im writing a function to get the parent and child ids but for the third loop there is a

problem the loop gets even the previous loops id also .

How can i avoid it?

<?
$results = '
<table>
    <thead>
        <tr >
            <td id="ticket" align="center" ><b>Task<br />ID</b></td>
            <td id="ticket" align="center" ><b>col1</td>
            <td id="ticket" align="center" ><b>col2</td>
</tr>
    </thead>
    <tbody>';

while ($row = mysqli_fetch_array($r, MYSQLI_ASSOC)) 
{
$results .='
        <tr >
            <td align="center">
                <a href="UpdateTask.php?TaskID='.$row['Task_id'].$filterstring.'">'.$row['Task_id'].'</a>
            </td>';

    $results .= '<td align="center">'; 
      $gg = mysqli_query($dbc,"select * from Ta开发者_Go百科sks where ParentTask_Id='".$row['Task_id']."'");
      echo "<br>";     
            while ($rowdd = mysqli_fetch_assoc($gg)) 
      {
       $results .= $rowdd['Task_id']."<br><br>"; 
       $gg2 = mysqli_query($dbc,"select * from Tasks where ParentTask_Id='".$rowdd['Task_id']."'");
       while ($rowdd2 = mysqli_fetch_assoc($gg2)) 
      {
         $results2 = $rowdd2['Task_id']."<br><br>";
      } 
      echo "<br>";    
      } 
    // $results .= $car ;
        // $results .=  $t; 
            $results .='</td>';
             $results .=' <td  align="left" >'?>
        <?
        $results .= $results2;  
        $results .='</td>';
$results .='
        </tr>';
}
?>

Is the $results variable empty? I only see it being concatenated.

Also, on your table you have multiple ids that are the same. You either need to change that to a class or have a unique value for each id.