Sorry I wasn't really awake, and didn't notice which list you'd posted on
:-) Here's an example in PHP (not tested):
==============================================
$cat_list = array();
$sql = "select id, parent_id, category from your_table where order by
parent_id, category ";
$res = mysql_db_query($dbName, $sql) or die("Fejl ved query: $sql<hr>" .
mysql_error());
while ($row = mysql_fetch_assoc($res))
$cat_list[] = $row;
showcattree(0, 0, $cat_list);
function showcattree($parent_id, $niveau, &$cat_list) {
$tabStr = str_repeat(" ", $niveau*3);
for ($i=0; $i<count($cat_list); $i++) {
$local_id = $cat_list[$i]["id"];
$local_parent_id = $cat_list[$i]["parent_id"];
$local_navn = $cat_list[$i]["titel"];
if ($local_parent_id == $parent_id) {
echo "$tabStr$local_navn<br>";
showcattree($local_id, $niveau+1, $cat_list);
$count++;
}
}
}
==============================================
Please note that cat_list is given as a by-reference parameter. Otherwise
you'd be copying the whole array for each recursive function call.
The trick is, that to make a tree you always need to use recursive
functions. The performance is gained by loading the complete list from
database at once (instead of calling a mysql SELECT statement for each
branch of the tree).
- Carsten
> -----Oprindelig meddelelse-----
> Fra: Carsten Gehling [mailto:[EMAIL PROTECTED]]
> Sendt: 27. maj 2002 20:33
> Til: [EMAIL PROTECTED]
> Emne: SV: building tree view in mysql?
>
>
> Well you'll neew to do some coding in your application language.
> What are you using to connect to MySQL? Perl? PHP? Java?
>
> Tell me, and I'll give you an example where you only query the
> database once (for optimum performance).
>
> - Carsten
>
> > -----Oprindelig meddelelse-----
> > Fra: Sagi Bashari [mailto:[EMAIL PROTECTED]]
> > Sendt: 27. maj 2002 20:50
> > Til: olinux; [EMAIL PROTECTED]; [EMAIL PROTECTED]
> > Emne: Re: building tree view in mysql?
> >
> >
> >
> > Yeah, thats exactly what I wanted to do. But how do I make MySQL sort it
> > like that? Show the parent first, and then all its childs, so the
> > application can determite if it's subcategory by checking if
> the parent is
> > was changed.
> >
> > Sagi
> >
> > From: "olinux" <[EMAIL PROTECTED]>
> >
> >
> > > create a table like this:
> > > id | parent_id | category
> > >
> > > parent_id points to the parent categories id. Top
> > > level categories get parent_id of '0'
> > >
> > > ex:
> > > 1 | 0 | auto
> > > 2 | 1 | repair
> > > 3 | 2 | body
> > > 4 | 2 | windshields
> > > 5 | 1 | detailing
> > > 6 | 2 | tires
> > >
> > > Tree would look like:
> > > auto
> > > repair
> > > body
> > > windshields
> > > tires
> > > detailing
> > >
> > > olinux
> > >
> >
> >
> >
> >
> > ---------------------------------------------------------------------
> > Before posting, please check:
> > http://www.mysql.com/manual.php (the manual)
> > http://lists.mysql.com/ (the list archive)
> >
> > To request this thread, e-mail <[EMAIL PROTECTED]>
> > To unsubscribe, e-mail
> > <[EMAIL PROTECTED]>
> > Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
> >
> >
---------------------------------------------------------------------
Before posting, please check:
http://www.mysql.com/manual.php (the manual)
http://lists.mysql.com/ (the list archive)
To request this thread, e-mail <[EMAIL PROTECTED]>
To unsubscribe, e-mail <[EMAIL PROTECTED]>
Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
