Doing a foreach and ordering using $i++; for example but depending on a parent id in PHP

question updated:

I've the next array, obtained from a nested sortable tree. 开发者_StackOverflowThe $key means the id of a PAGE and the $value it's the parent id. In my MySQL table I've to modify the parent_id of every page (when updating) and store the ORDER of a PAGE depending of the parent ID.

In the next example I've 3 ids with parent_id = 1: 5, 2 and 3. I've to update on MySQL 5,2 and 3 saving like:

UPDATE pages SET parent_id=1,order=0 WHERE id=5
UPDATE pages SET parent_id=1,order=1 WHERE id=2
UPDATE pages SET parent_id=1,order=2 WHERE id=3

Array
(
    [1] => 0
    [5] => 1
    [2] => 1
    [3] => 1
    [4] => 3
    [6] => 3
)

How I can handle this with PHP? I'll do a foreach for every page id and send a MySQL update on each of loop for the foreach?

Thank you in advance!

I think you'll just want to use another variable to keep track of the last parent id used and then compare to see if it changed.

// make sure the array is sorted by parent id
asort($array);

$last_parent = -1;
foreach ($array as $id => $parent_id)
{
    if ($last_parent != $parent_id)
        $order = 0;

    $query = 'UPDATE pages SET parent_id = ' . $parent_id . ', order = ' . $order . ' WHERE id = ' . $id;

    $last_parent = $parent_id;
    $order++;
}

Are you saying that you want to order the array based on the value?

In which case you would use

sort($array);