array_multisort ? how do I code this?

[cgchris99]

I have some code that retrieves a list of dealers.
I need to sort thsi list on a field that doesn't exist in the tables.

Distance from customer will be the field (I have a function for this)

I can calculate this but once I get the distance how do I resort the list in ascending order by distance

The code below displays all the dealers but not the closest one first. It is pretty random. Like I said I know how to calculate the distance but don't know how to create a new array for this data and sort it.

Not sure array_multisort is what I need
Thanks for any advice.

Here is some pseudo code that I am using

$query = tep_db_query("SELECT * FROM dealers inner join zipcode on dealers.zip = zipcode.zipcodeID WHERE " . ($crit_str) );

$totalfound = mysql_num_rows($query);

    for ($i = 1; $i <= $totalfound; $i++)
     {
        $rs1rec = tep_db_fetch_array($query);
        $INFO_DESCRIPTION .= '<b>' . $rs1rec['name'] . '</b><br>';
        $INFO_DESCRIPTION .= $rs1rec['address'] . '<br>';
        $INFO_DESCRIPTION .= $rs1rec['city'] .', '.$rs1rec['state'] .' '. $rs1rec['zip']  . '<br>';
        $INFO_DESCRIPTION .= $rs1rec['phone'] . '<br><br>';
        $INFO_DESCRIPTION .= $rs1rec['latitude'] . '<br>';
        $INFO_DESCRIPTION .= $rs1rec['longitude'] . '<br><br>';
     }

[vaanil]

Hi,

Adding the distance information into the existing array should not be too tough. Once you have the $rs1rec array, you could calculate the distance and add into the same array by something like $rs1rec['distance'] = $distance.

You could create a new array by choosing the unique key from each of your rows. example

$combined_array = new array();
for ($i = 1; $i <= $totalfound; $i++)
{
$distance = calculateDistance();
$key = [ find the suitable key here]
$combined_array[$key] = $rs1rec;
}

I am not very sure about the array_multisort. But if you cant get it right, you could add distance as part of the key and sort the array, so that it will be sorted as you want.

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[Weedpacket]

If you calculate the distance from the customer for each dealer and add it to the array as a new element, it would be easy to take two dealers and see "which is further". Then usort() would do the hard work of using that comparison to sort the entire array. (I wrote something on the subject here a while back.)

But this question has cropped up more than once in the past with the idea of calculating the distance in the database itself (usually because only some of the records are wanted, such as those within a certain distance). e.g.,
http://www.phpbuilder.com/board/showthread.php?t=10308939&highlight=distance
http://www.phpbuilder.com/board/showthread.php?t=10290629&highlight=distance
http://www.phpbuilder.com/board/showthread.php?t=10306916&highlight=distance
http://www.phpbuilder.com/board/showthread.php?t=10292374&highlight=distance

There are others.