>I have a table with id, pid(parent), title and page_name(url) fields.
>
>The vars provided to the script are the current page's title, id and
>pid(parent)
You can look up the parent and in the database, so it's not horribly
important that those be provided.
*UNLESS* you have a heterarchy, and not a hierarchy -- In other words,
*UNLESS* there are two different "paths" to get to 'id' through different
parents. In other other words, *UNLESS* you have duplicate id's in the
database... If you *DO* have a heterarchy, you'd need to track the user's
path as they traveled to know which route to display.
I'll assume you don't have a heterarchy, for now.
>When I am on the parent page I get this(Which is what I want):
>[ Chronological History ][ Website Chronological History ]
>
>When I am in the Child I get this:
>
>[ Website Chronological History ][ Website Chronological History ]
>
>What am I doing wrong???
You really can't get all the parents in one SQL statement.
You'll need to look up the parent. Then the grand-parent. Then the
great-grand-parent. And so on.
Each with a different SQL query.
Now, this is not ideal for performance.
In fact, it's *HORRIBLE* if (A) your tree is really "deep" -- If you have 10
generations of "depth" to the ggggg'great-grand-parents, then it's gonna
take 9 queries to look it up.
If you're only looking at three or four levels, it's really no big deal...
Unless your site is, like, getting a zillion hits.
Let's assume it's not getting a zillion hits for now, okay?
>I have stared at this two many times now and am probably missing the obvious
>
>function menu($id, $pid, $title) {
> $query = "select * from meta_data WHERE pid = '$id' OR pid = '$pid' &&
>pid != 0";
This will give both the current record and the parent record, but never,
ever, ever, the grand-parent record...
> $result = mysql_query($query);
> $num_results = mysql_num_rows($result);
> if($num_results != 0){
> ?>
><table width="100%">
><tr><td align="center">
> <?
> echo '[ '.$title.' ]';
> for ($i=0; $i < $num_results; $i++)
> {
> $row = mysql_fetch_array($result);
> if($id == $row['id']){
> echo '[ '.$row['title'].' ]';
> } elseif($row['pid'] == $id || $row['id'] == $pid && $pid != 0) {
> echo '[ <a
>href="'.$row['page_name'].'">'.$row['title'].'</a> ]';
> }
> }
> ?>
></td></tr>
></table>
> <?
> }
Try something more like this:
function menu($id){
$query = "select pid, title from meta_data where id = $id";
$meta = mysql_query($query) or error_log(mysql_error()); # Check HTTP
error_log for SQL errors!
list($pid, $title) = mysql_fetch_row($meta, 0);
if (isset($pid) && $pid)){
# Switch the menu() and $title parts around if you want bread-crumbs in
the other direction
$result = menu($pid) . $title;
}
else{
$result = '';
}
return $result;
}
NOTE:
There *ARE* techniques for encoding the SQL in such a way that a single SQL
statement can get the entire "path" at once, but they get kinda complicated
and gnarly, and, really, as I said, if you have a shallow tree, it's just
not worth the hassle... If you have a really *DEEP* tree, you'll need to do
some more research.
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