Removing duplicates from a two table list

[rgEffects]

I have some code that creates a very nice indented list like this:

• first item
• second item
  • Child of Second Item
• third item

Table A has a column for id, childID and name. The code works just fine for a single table but if I want to add another table and remove the duplicates using WHEN tableB.tableAChildID = tableA.childID I get no results. Here's the code that is not working:

PHP Code:

<?php
    $parentid = 0; // assuming that 0 is the main category.
    get_sub_cats($parentid);
    function get_sub_cats($parentid) {
    
    $sql = "SELECT
    tableA.id, tableA.childID, tableA.name,
    tableB.tableAchildID
    FROM tableA, tableB
    WHERE tableA.childID = ".$parentid."
        AND tableA.childID = tableB.tableAChildID
    "; 
    $countID = $rec['tableA.id'];
    $run = mysql_query($sql);
    $newLink = "'bizCatEdit.php?recordID=" ;
    $hypnen = "'";
    echo '<ul class="aqtree3clickable">';
        while ($rec = mysql_fetch_assoc($run)) {
        echo '<li />SN:', $rec['id'], ' - ',  $rec['bcName'], ' / ', $rec['BBS']; 
        get_sub_cats($countID);
        }
    echo '</ul>';
    }
    ?>

If I remove the AND method I end up with a table that looks like this:

• first item
• first item
• first item
• second item
• second item
• second item
• Child of Second Item
• Child of Second Item
• Child of Second Item
• third item
• third item
• third item

Removing

PHP Code:

 $countID = $rec['tableA.id']; 


and changing the line

PHP Code:

 get_sub_cats($countID); 


to

PHP Code:

 get_sub_cats($rec['id']); 


Brings back the indents like this:

• first item
• first item
• first item
• second item
  • Child of Second Item
• second item
  • Child of Second Item
• second item
  • Child of Second Item
• third item
• third item
• third item

Any ideas how I can remove the duplicates?