data persistence

sayray

I am building a set of search functions. One of the search components is a multiple list combo box for different towns. So the user can choose more than one town to search in in selection. No big deal here, I just pass an array.
The question I have is when I go to pass the information with a pagination script. My pagination script uses a prev/next link which passes the query over the url. However, there is also multiple items other than town to search with so this query can get pretty large. Here is and example of my query...

$query = "SELECT * FROM $table ";
$whereArray = array();

$cityCount = count($cities);
for($i=0; $i<$cityCount ; $i++)
{
$whereArray[] = "CIT='".$cities[$i]."' 
AND BR BETWEEN '$br1' AND '$br2'
AND BTH BETWEEN '$bth1' AND '$bth2'
AND TYP = '".$type."'";
}

$combined = implode( " OR ", $whereArray);

if ($combined != "")
{
   $query .= " WHERE ";

   if($combined != "")
  {
     $query .= $combined;
  }
}

if (isset($order)) { 
$query .= " ORDER BY " . $order. " " . $orderType . " ";
} else {
$query .= " ORDER BY ".$defaultOrder." ".$orderType." ";
	}

$query .= "LIMIT " . $index . "," . $offset;

I left quite a bit code out but this is to illustrate what I am doing. I can pass this query over a post form function, is there anyway I can pass it on the nex/prev button without being forced to use a form. I know you can't pass arrays over URL's so is there a way this can be done?

Weedpacket

Have you considered using PHP's [man]session[/man] support? Much more flexible, friendlier, and safer than trying to stuff everything into a URL (for which FYI you'd use [man]serialize[/man] and [man]urlencode[/man]).

bretticus

Well, first off, I'm sure your SQL statement could probably be much shorter, but then again, I can't pretend I know what you are after. The reason I mention this is because one of the methods I would suggest is to simply attach the sql query to the links. However, as I write this I am thinking that you need to send the multiselect values to repopulate the multiselect on a subsequent page load. Then again why not build the query again since you are passing the array each time via POST? Ok, now I'm babbling...

To answer your questions only...you can pass the array in a link (or via GET). simply use implode (or use the $combined value you already have) to make a long string and base64 encode it. On the next page load, decode it and and create a new array with it or simply insert the $combined value into your query this time.

If the GET value is too large (hence the length concern above) your web server may reject some of the data on the return trip (or possibly throw an error.)

and yes, as weedpacket points out, you can use a seesion variable and keep that lengthy string serverside, in fact, you can even store arrays as session values.