making category tree with php & mysql

[mlewczuk]

Hello group,
I'm working on a news system. It will allow users to add news etc. But what is most important for me (right now...) is to make good categorization of each news. Categorization means that we can link choosen news to some news categorys (then we will be able to search archive of news by specyfied categorys). Now, I have made in my mysql database something like this:

1. Group id
2. Main group id
3. Group name

So I can add new group and select if it is a new group, or subgroup of some group. For example, right now I have three groups (three records):

Group id | Main group id | Group name

1 | &nbsp | Economy news

2 | 1 | Local

3 | 2 | New York

4 | 1 | World

5 | 4 | Poland

And I have a problem with category tree in my php script. The script shoud generate something like this:

• Economy new
  &nbsp &nbsp+ Local
  &nbsp &nbsp&nbsp&nbsp&nbsp &nbspNew York
  &nbsp &nbsp+ World
  &nbsp &nbsp&nbsp&nbsp&nbsp &nbspPoland

It's not a problem to make this if we know how deep category tree is, but when we don't want to limit deepness of the tree it's more complex and I don't know how to do it.

Maybe you will help me.

[TTT]

basicly you can do it like this

$count = 0;
$total_index = 0;
$q[$count] = select id from x where parent = 0
while(...)
{
for([$i,{all fields, like id, parent name...}])
{
$recursearray[$totalindex][$i] = ...
}
$recursearray[$totalindex][{max i +1}] = $count

include("recurse2.php")
// recurse2 begins
$prev_id = $q[$count].id;
$count ++;
$q[$count] = select id from x where parent = $prev_id
while(...)
{
// array insert's
include("recurse2.php")

}
$count --;

}

[mlewczuk]

Hmm... thanks TTT for your answer, but can you write me more details (I mean, that it's hard for me to understand what you had on your mind... ). I would be thankful...