Tags and Keywords

I feel like a newbie... 10 years since my last post on usenet and still
fresh as ever. So to the point.
del.icio.us, flickr, technorati all have tag based systems. Therefore
I must have one as well. Stuck would be the place where I am now.
Below is the code that I have already and the table layout. I just
need a push in the right direction. I am using this as not only a
learn to do it project but who knows what the boss will think. Thanks
for any help.

The tables...

Three tables

bookmarks
tags_bookmarks
tags

tags_bookmarks is a two field linking table for the many to many
relationship between bookmarks and tags (primary id is combination of
the two liniking fields tagID and bookmarkID)

I have figured out how to add the data and link the records the trouble
is with getting the tags and the data out. Here's what I have so far.

function outputTags($tag) {
    if (!$tag) {
    $tag_array = $this->getRecords("SELECT tag FROM tags"); // A
simple place holding query
    } else {
    $tag_array = $this->getRecords("SELECT tag FROM tags"); // A simple
place holding query
    }
    $output = "<ul>";
    foreach ($tag_array as $tag) {
    $tag_name = $tag['tags'];
    $output .= "<li><a href=\"view_marks.php?link_tag=" . $tag_name .
"\">" . $tag_name . "</a></li>";
    }
    $output .= "</ul>";
    return $output;
  }
 
  function getBookmarks($tag) {
   $bookmarks = $this->getRecords("SELECT bookmarks.* FROM bookmarks,
tags, tags_bookmarks WHERE bookmarks.bookmarkID =
tags_bookmarks.bookmarkID AND tags_bookmarks.tagID = tags.tagID AND
tags.tag = '$tag'");
   $output = "<ul>";
   foreach ($bookmarks as $b) {
    $title = $b['title'];
    $url = $b['url'];
    $output .= "<li>" . $title . "</li>";
   }
   $output .= "</ul>";
   return $output;
  }

It is the trouble I think ( and I could be so wrong it's not funny)
with the SQL statements and getting the right data. What I want it to
do is when I first click/select a tag is looks up all the related tags
and shows just the related tags. Therefore, when I click the tag
"Software" I want to see all the bookmarks and Tags that are associated
with "Software", however I also want to be able to dig down into the
tags. I want to be able to go down into the tags list, but not like
del.icio.us, that just keeps showing all the tags again. What I want
to happen is if I click "Software" and then click "OS X" I only want to
see tags associated with "Software" AND "OS X".... and of course the
bookmarks that go with it. I hope that explains the issues that I am
having. Any ideas or pointers? Again thanks for any help.

A.<!-- ~MESSAGE_AFTER~ -->

Andrew wrote:
 > I feel like a newbie... 10 years since my last post on usenet and still
 > fresh as ever. So to the point.
 > del.icio.us, flickr, technorati all have tag based systems. Therefore I
 > must have one as well. Stuck would be the place where I am now. Below
 > is the code that I have already and the table layout. I just need a
 > push in the right direction. I am using this as not only a learn to do
 > it project but who knows what the boss will think. Thanks for any help.
 >
 > The tables...
 >
 > Three tables
 >
 > bookmarks
 > tags_bookmarks
 > tags
 >
 > tags_bookmarks is a two field linking table for the many to many
 > relationship between bookmarks and tags (primary id is combination of
 > the two liniking fields tagID and bookmarkID)
 >
<SNIP>
 > It is the trouble I think ( and I could be so wrong it's not funny) with
 > the SQL statements and getting the right data. What I want it to do is
 > when I first click/select a tag is looks up all the related tags and
 > shows just the related tags. Therefore, when I click the tag "Software"
 > I want to see all the bookmarks and Tags that are associated with
 > "Software", however I also want to be able to dig down into the tags. I
 > want to be able to go down into the tags list, but not like del.icio.us,
 > that just keeps showing all the tags again. What I want to happen is if
 > I click "Software" and then click "OS X" I only want to see tags
 > associated with "Software" AND "OS X".... and of course the bookmarks
 > that go with it. I hope that explains the issues that I am having. Any
 > ideas or pointers? Again thanks for any help.

How are you storing the relationships between tags? i.e. how does your
database know that the "OS X" tag is associated with the "Software" tag?

--
Oli<!-- ~MESSAGE_AFTER~ -->