Element ordering

[mb81]

Hey Guys,

 

I have a project where the user is able to select the order of items for display using up and down buttons. I have used systems like this before, but have run into problems with gaps in the sequencing or getting duplicate numbers in the ordering sequence. Are there any algorithms that other people have used for this type of thing?

 

Thanks,

Matt

[Jessica]

I know what you're talking about, but I don't understand the problem? What is your problem with the gaps and duplicate numbers?

 

I usually loop through the results of the user's ordering and assign them into an array, so that removes the gaps/dupes.

[roopurt18]

table {field1, field2, field3, ...}

elements {id, name, order, ...}

 

Let them designate the order as an integer, but when you display the items don't display the order thats in the table, display an order from a counter variable.

 

SELECT * FROM elements WHERE 1 ORDER BY order;

 

<?php
$q = mysql_query($sql);
if($q){
  $count = 1;
  while($row = mysql_fetch_assoc($q)){
    echo $count++ . ": " . $row['name'];
  }
}
?>