Click on name changes order of column

[kilbey1]

I wasn't sure what to search under, and didn't find anything after trying some words, so I apologize if this has been answered before.

Using info in a database, how would I go about setting links to change the order in which my information is presented?

IE:

| ID | Name | Manufacturer

When the user clicks on NAME, information is ordered by name, manufacturer by manufacturer, etc.

• Eve

[Weedpacket]

Add a bit of querystring to the colum head links; linking back to the same URL, and with "?sortby=name&sortdir=asc" or "?sortby=id&sortdir=desc" or whatever is appropriate ("sortdir" is given so that if they're already sorted in ascending order, clicking it again lists them in descending order, and vice versa).

Then in the script retrieving the stuff from the database:

$sort='';
switch($_GET['sortby'])
{
case 'id': $sort .= "id"; break;
case 'name': $sort .= "name"; break;
case 'manufacturer': $sort .= "manufacturer"; break;
default: break;
}
// Where the value appended to $sort
// is the name of the relevant field
if($_GET['sortdir']=='desc')
  $sort.=' DESC';
elseif($_GET['sortdir']=='asc')
  $sort.=' ASC';

Build your $query up to where the ORDER BY clause would go (if there is a LIMIT clause, leave it off for now), and then go

if($sort!='')
  $query.= ' ORDER BY '.$sort;

And then tack on the LIMIT clause if there is one.

'Course, I've seen this done entirely client-side in Javascript; but too many people are still faffing around with noncompliant browsers...

[kilbey1]

GREAT! Mostly working. 2 questions.

1. Correct syntax for a link using $_PHPSELF like so:
   <td align="center"><b><a href="$PHP_SELF?sortby=name&sortdir=desc">Product Name</a></b></td>

2. I don't understand the DIR portion. I've got it set up like this and can't run it.

if($_GET['sortdir']=='desc') {
  $sort.=' DESC';
} else {
  $sort.=' ASC';
}

Can you point out what I'm missing here to make the DESC and ASC work?

Thanks,
Eve

[Weedpacket]

1. Correct syntax for a link using $PHPSELF like so:
   <td align="center"><b><a href="$PHP_SELF?sortby=name&sortdir=desc">Product Name</a></b></td>
   Uh-huh. I generally use $SERVER['PHP_SELF'], myself because I prefer to have register_globals turned off. If it's bare HTML, then you will of course need to specify PHP mode (i.e., <?php ) at an appropriate moment; e.g.

   <td align="center"><b><a href="<?php echo $_SERVER['PHP_SELF']?>?sortby=name&sortdir=desc">Product Name</a></b></td>
   

2.
I don't understand the DIR portion. I've got it set up like this and can't run it.

How do you mean "can't run it"? I did change my mind partway through; I originally called the field "dir" before deciding "sortdir" was a better name. Just forgot to update some of the occurrences of "dir" in the post. I also corrected there a bug that would cause grief if $_GET['sortdir'] was empty for some reason (like: none of the columns had been clicked yet). Another fix would have been to just drop the else branch; any ordering would be done ASC by default anyway.

[kilbey1]

Thanks, Weedpacket. Works great. 🙂

I just took the sortdir portion out; it's really not essential for this application. When I said I couldn't 'get it to to run', I meant it sorted the way I wanted to by order, but not DESC or ASC depending on click.

• Eve