Linux, Apache, MySQL, PHP

id   page     parent
1    index    0
2    about    1
3    products 1
4    cars     3
5    trucks   3

first pass:
$bc = "/"."trucks";

second pass:
$bc = "/"."products".$bc;

third pass:
$bc = "/"."index".$bc;

$myURL=$_SERVER["REQUEST_URI"];
AddPageToPageTable("shortNameSeenInBreadCrumb", "MyParentsShortName", $myURL);

id   page     parent
1    index    0
2    about    1
3    products 1
4    cars     3
5    trucks   3

<?php
  $bc_arr = array();
  $depth_guage = 0; // this is used to measure the relative path depth
  $home_not_found=true; // home is any top level page marked aa zero in the database table.
  $cur_pg_name = ""; // set to a name of the current page dynamically...

  while($home_not_found)
  {
    // I have not tested this query, but I hope you can follow the logic. If it does not work you may need to split the logic out.
    $sql = "select pr1.*, (select pr2.page from page_relations as pr2 where pr2.id=pr1.parent) as parrent_name, (select pr2.parent from page_relations as pr2 where pr2.id=pr1.parent) as grandparent from page_relations as pr1 where page='".$cur_pg_name."'";
    $rst = mysql_query($sql) or die(mysql_error();
    $row = mysql_fetch_row($rst);

    // if the grand parent is == 0 then stop the loop.
    if($row['grandparent']==0)
    {
      $home_not_found=false;
      //.. build and assign breadcrumb link to array. see below
      //.. also include parent link
    }
    else
   {
      //...build and assign breadcrumb link to array. see below
      //...assign parent name to $cur_pg_name
   }
    // you are below, this should be in the if/else of the loop
    //...each pass
    array_push($bc_arr,"<a href='".str_repeat("../",$depth_guage).$row['page'].".php'> > ".$row['page']."</a>");
    $depth_guage++;
?>

$Results=mysql_query($query);
if (!$Results) die("DB Error in WriteQuery ($query)".mysql_error());

echo "<pre>";
print_r($_GET);
print_r($_POST);
print_r($_SESSION);
echo "</pre>";