tutorials on this?

[Jonathan]

Anybody know of **simple** tutorials on how
to build scripts that use parental/children IDs?

I want an actual tutorial, as my PHP book has
a chapter purely dedicated to build a forums system,
yet I do not understand much of how it works

Basicly I want to use it for several reason:

1) Links directory, matching certain links
only to the "category ID" that matchs the 'parent ID'

2) News Script with comments, matching comments
only to the news article ID that matchs the 'parent ID'

3) Pre-lude for an *extremely* simple forums possibly?

[Buddha]

For an extremely simple forum, you may not need a very complicated parent/child relationship, as in no threaded discussions.

TABLE thread
thread_id # parent
thread_title
thread_author
thread_published
thread_text

TABLE comment
comment_id # child
thread_id
comment_title
comment_author
comment_published
comment_text

To display a list of topics is simple:

SELECT thread_id, thread_title, thread_author, thread_published 
FROM thread
ORDER BY thread_published DESC
LIMIT 0, 5

To display a topic isn't much harder:

# GET THE TOPIC
SELECT * FROM thread
WHERE thread_id = '$id'
LIMIT 1

# GET THE COMMENTS
SELECT *
FROM comment
WHERE thread_id = '$id'
ORDER BY comment_published ASC
LIMIT 0, 5

Here I used two tables for clarity but you could do it with just one. As you can see the fields over lap.

[Jonathan]

Awsome Buddha; that confirms what I was trying to do,
but it didn't seem to work on my computer (uploaded and worked fine);

Basicly, I want to set a links directory, where only show
links if the 'cat_id' matchs the 'id', and if not show an generic message

[Buddha]

Awsome Buddha; that confirms what I was trying to do,
but it didn't seem to work on my computer (uploaded and worked fine);

Hope you didn't try to run that it was just pseudocode.

Basicly, I want to set a links directory, where only show
links if the 'cat_id' matchs the 'id', and if not show an generic message

I wasn't sure what you meant by that the first time and I'm still not sure either? It sounds like you want a collections of links that are associated with a catagory.

TABLE link
link_id
link_url
link_title
link_alt_text
catagory_id

TABLE catagory
catagory_id
catagory_name

SELECT t1.link_url, t1link_title, t1link_alt_text, t2.catagory_name
FROM link AS t1, catagory AS t2 
WHERE catagory_id = $id
AND t1.catagory_id = t2.catagory_id

Of course you'll have to make that JOIN work in whatever database your using.

To figure out what to display just see how many rows were returned.

IF ( num_rows( $result ) > 0 ) THEN
    DISPLAY_RESULTS();
ELSE
    DISPLAY_DEFAULT_MESSAGE();
ENDIF