计算一个类别中的所有子类别

Question

I have database with following columns:

id, parent, name, description

The idhas been set to auto incerement. I want to get total number of all the subcategories that are inisde the parent category (which has it's parent set to 0) I also want this to be reccursive. What can be the fastes way of doing so?

I already wrote the following function but I can not test it at the moment:

function CountDeepSubCategories($parentID, $max = 0)
{
    global $_DB;

    $all = $all + $max;

    $q = $_DB->Query("SELECT id FROM category_cats WHERE parent = $parentID");
    $id = $_DB->GetResultValue($q, 0, 'id');

    $num = $_DB->GetResultNumber($q);       

    for($i = 0; $i < $num; $i++)
    {
         CountDeepSubCategories($id, $all);
    }

    return $all;        
}

Answer 1

does every category have a parent? if that you can do "select count(*) from category_cats" :)

ok, for the second comment that you've posted, why dont you just add an insider query like this:

select cct.id,
    (select count(1) from category_cats where parent=cct.id) as subcount
from category_cats cct

i've not tested it but it should work.