Sorting array with different values..

benbox

Hey all!

I've come across a little thing which I'm trying to work out the best/most efficient way of doing.. or then again, just how to do it to begin with!

Basically what I'm doing is pulling a load of member ID's from a mysql table, which I then use to return the respective username from another table. However these output from my while (mysql_fetch_array) loop in order of the ID ordered ASC.

What I want to do, is reorder the output so that they are printed out by the username, alphabetically.. but I also need to keep the user ID for use on the page.

I just tried to have 2 parallel arrays, both numerically referenced, so I could do a for loop for 0 to count(array_length).. but obviously if I used sort($nameArray) this would put the reference numbers out of sync..

So, my question is how can I do this?

This is basically the code I have so far, with my attempts removed because they are just silly! I think I somehow need to put them into another array, then sort() it.. but I'm not sure how to keep both values (ID and name) in the array..

<?php
$sql = sprintf("SELECT * FROM %s WHERE group_id = %s ORDER user_id ASC", DB_USER_GROUP_MEMBERS, $_GET['id']);
$group_query = mysql_query($sql);

while( $group = mysql_fetch_array($group_query) )  {
	$id = $group['user_id'];
	$name = dbFieldReturn("user", DB_USERS, "id", $group['user_id']);
}

//sort($group_array);
for($k=0; $k<count($group_array); $k++) {
?>
	<option value="<?php echo //ID; ?>"><?php echo //name; ?></option>
<?php	
}
?>

benbox

Ok, I've just figured out I can do this:

while( $group = mysql_fetch_array($group_query) )  {
	$group_array[] = array ( "name" => dbFieldReturn("user", DB_USERS, "id", $group['user_id']),
							 "id" => $group['user_id'] ) ;
}

But I still can't quite figure out how to sort that alphabetically.. because this doesn't seem to work, I think because it's still sorting buy the first [] which is already in order?

sort($group_array[]['name']);

benbox

I think I'm being very stupid here.. I think I might have it... just simply sort($group_array).. but how does it know to sort the name and not the ID, is it just on a first come first served basis?

It appears to be working now, but I don't trust it.. it might be just a coincidence that the members happen to be in the order they are..

laserlight

You can just dump the rows of the result set into an array:

$group_array[] = array();
while ($row = mysql_fetch_assoc($group_query)) {
	$group_array[] = $row;
}

Now use [man]usort/man and [man]create_function/man.

Let's say you want to sort by name:

usort($group_array, create_function('$a,$b', 'return strcmp($a["name"],$b["name"]);'));

or if you want to sort by user_id:

usort($group_array, create_function('$a,$b', 'return $a["user_id"]-$b["user_id"];'));