This is kinda more of logic question, because I already know how to code it, but it's coded in PHP/MySQL so I thought I'd post here.


I have a site, where users can register/login.
The user gets their own homepage where they can add different sections and links inside each section.

My problem is what to do with the order of the links. I want users to be able to customize the order.

What I've done so far is:

Each link has a 'place', which is just a number.

When you add a link, it get's the place of the last link in that section, and adds one, so as to put it in last place.

When you delete a link, it removes that link, then subtracts 1 from every links 'place' that come after it.


Now I want to make it so users can change the place. And I don't really know how I should go about it.

I guess you'd pick a new place for it, and some how renumber all the ones after it.

It's really confusing, is there any easier ways? Or how about examples


This is the current code when something get's deleted:

PHP Code:

            $placesql = mysql_query("SELECT * FROM sections WHERE column_id = '$deletedcolumn' AND place > '$deletedplace'");
            
            while ($needsupdate = mysql_fetch_array($placesql)) {
             
            $newpid = $needsupdate[id];
            $newp = $needsupdate[place] - 1;
            
            mysql_query("UPDATE sections SET place = '$newp' WHERE id = '$newpid'");
            } 


I'm assuming the move code will have to be longer.



If anyone has any thoughts on this subject, I'd appreciate it.

Sorry for a rather messy post.

One way would be to allow the user to assign priorities to each link. A link with a higher priority is displayed first. Links with equal priority are displayed in whatever order they are retrieived from the database. This lets you just select the links and sort by priority, without actually worring about assigning unique positions to each link.

You can also use something like this:

PHP Code:

<?php
// $new_position is defined to be the new place number for the column_id
// $column_to_move is defined to be the column you wish to move.

mysql_query("UPDATE sections SET place = place + 1` WHERE place >= '".$new_position."'");
mysql_query("UPDATE sections SET place = ".$new_position."` WHERE column_id=".$column_to_move);
?>

Now, I've only taken a guess at the names based off of what you provided since you didn't include the table structure for your sections table, but it should give you the idea.

You'll note also that it is not necessary to loop through each result and update as I've shown in the code above, so you can modify your current routines.

One thing of concern is that your queries seem to have nothing filtered by a specific user or account, so these changes will apply to all entries within the sections table -- not likely something you'd intended.