Question

Can you help me get this breadcrumb navigation work. My php is not good. i am still learning.

This is my cats in mysql

cats_id   cats_position   cats_parentid 

1            1>                0
2            1>2>              1
3            3>                0
4            1>2>4>            2

I tried something like this but it is not the proper way. Can you please show me the proper way.

$pieces = explode(">", $position);

if ($pieces[0] != "")
{

 $result = mysql_query("SELECT * FROM cats
 WHERE cats_id='$pieces[0]'");
 while($row = mysql_fetch_array($result))
   {
$piecesid0 = $row['cats_id'];
$piecesname0 = $row['cats_name'];
$piecesposition0 = $row['cats_position'];
   }
}
if ($pieces[1] != "")
{
 $result = mysql_query("SELECT * FROM cats
 WHERE cats_id='$pieces[1]'");
 while($row = mysql_fetch_array($result))
   {
$piecesid1 = $row['cats_id'];
$piecesname1 = $row['cats_name'];
$piecesposition1 = $row['cats_position'];
   }
}
if ($pieces[2] != "")
{
 $result = mysql_query("SELECT * FROM cats
 WHERE cats_id='$pieces[2]'");
 while($row = mysql_fetch_array($result))
   {
$piecesid2 = $row['cats_id'];
$piecesname2 = $row['cats_name'];
$piecesposition2 = $row['cats_position'];
   }
}
if ($pieces[3] != "")
{
 $result = mysql_query("SELECT * FROM cats
 WHERE cats_id='$pieces[3]'");
 while($row = mysql_fetch_array($result))
   {
$piecesid3 = $row['cats_id'];
$piecesname3 = $row['cats_name'];
$piecesposition3 = $row['cats_position'];
   }
}
?>
<a href="index.php">Index</a> > 

<a href="cats.php?cat=<?=$piecesid0;?>&parent=0&position=<?=$piecesposition0;?>"><?=$piecesname0;?></a>

<?
If ($piecesid1 != "")
{
?>
> <a href="cats.php?cat=<?=$piecesid1;?>&parent=<?=$piecesid0;?>&position=<?=$piecesposition1;?>"><?=$piecesname1;?></a>
<?
}
?>
<?
If ($piecesid2 != "")
{
?>
> <a href="cats.php?cat=<?=$piecesid2;?>&parent=<?=$piecesid1;?>&position=<?=$piecesposition2;?>"><?=$piecesname2;?></a>
<?
}
?>
<?
If ($piecesid3 != "")
{
?>
> <a href="cats.php?cat=<?=$piecesid3;?>&parent=<?=$piecesid2;?>&position=<?=$piecesposition3;?>"><?=$piecesname3;?></a>
<?
}
?>

Answer 1

Take a look here at the nested set model:
http://mikehillyer.com/articles/managing-hierarchical-data-in-mysql/

This is how CakePHP implemented the Tree behavior, which is what I use for breadcrumbs. They added the parent_id column as an enhanced version of nested set.

If that is too heavy weight, you can use the Adjacency List Model: http://kod34fr33.wordpress.com/2008/05/06/adjacency-list-tree-on-mysql/