PHP List Hierarchy

[litewarez]

The problem is that most programmers including the better ones will always do recursive calls to the database, causing higher load on the DB.

You can do this in a single pass, using PHP References.

Example:

$refs = array();
$list = array(); //This is the baby

$result = mysql_query("SELECT * FROM releases");

while($data = @mysql_fetch_assoc($result))
{
    //Cfreate / Select a referenced variable in the memory
    $thisref = &$refs[ $data['id'] ];

    //Set the parent id
    $thisref['parent'] = $data['parent'];

    //Set the data as your going to need it later
    $thisref['data'] = $data;

    //If its not a root, set the referenced array
    if ($data['parent'] == 0)
    {
        $list[ $data['id'] ] = &$thisref;
    }
    else
    {
        $refs[ $data['parent'] ]['children'][ $data['id'] ] = &$thisref;
    }
} 

Example of why references works is like so:



The code above will replicate hierarchy in a PHP