I need to sort on a date-field type, which name is "mod_date".

It works like this in the browser adress-bar:

   http://localhost:8983/solr/select/?&q=bmw&sort=mod_date+desc

But I am using a phpSolr client which sends an URL to Solr, and the url sent is this:

 fq=+category%3A%22Bilar%22+%2B+car_action%3AS%C3%A4ljes&version=1.2&wt=json&json.nl=map&q=%2A%3A%2A&start=0&rows=5&sort=mod_date+desc

 // This wont work and is echoed after this in php:

 $queryString = http_build_query($params, null, $this->_queryStringDelimiter);
 $queryString = preg_replace('/%5B(?:[0-9]|[1-9][0-9]+)%5D=/', '=', $queryString);

This wont work, I dont know why!

Everything else works fine, all right fields are returned. But the sort doesn't work.

Any ideas?

Thanks

BTW: The field "mod_date" contains something like:

    2010-03-04T19:37:22.5Z

EDIT:

First I use PHP to send this to a SolrPhpClient which is another php-file called service.php:

    require_once('../SolrPhpClient/Apache/Solr/Service.php');
    $solr = new Apache_Solr_Service('localhost', 8983, '/solr/');
    $results = $solr->search($querystring, $p, $limit, $solr_params);

$solr_params is an array which contains the solr-parameters (q, fq, etc).

Now, in service.php:

            $params['version'] = self::SOLR_VERSION;

    // common parameters in this interface
    $params['wt'] = self::SOLR_WRITER;
    $params['json.nl'] = $this->_namedListTreatment;

    $params['q'] = $query;
    $params['sort'] = 'mod_date desc'; // HERE IS THE SORT I HAVE PROBLEM WITH

    $params['start'] = $offset;
    $params['rows'] = $limit;
            $queryString = http_build_query($params, null, $this->_queryStringDelimiter);
            $queryString = preg_replace('/%5B(?:[0-9]|[1-9][0-9]+)%5D=/', '=', $queryString);

     if ($method == self::METHOD_GET)
    {
 return $this->_sendRawGet($this->_searchUrl . $this->_queryDelimiter . $queryString);
    }
else if ($method == self::METHOD_POST)
    {
    return $this->_sendRawPost($this->_searchUrl, $queryString, FALSE, 'application/x-www-form-urlencoded');
    }

The $results contain the results from Solr... So this is the way I need to get to work (via php).

This code below (also on top of this Q) works but thats because I paste it into the adress bar manually, not via the PHPclient. But thats just for debugging, I need to get it to work via the PHPclient:

  http://localhost:8983/solr/select/?&q=bmw&sort=mod_date+des // Not via phpclient, but works

UPDATE (2010-03-08): I have tried Donovans codes (the urls) and they work fine. Now, I have noticed that it is one of the parameters causing the 'SORT' not to work. This parameter is the "wt" parameter. If we take the url from top of this Q, (fq=+category%3A%22Bilar%22+%2B+car_action%3AS%C3%A4ljes&version=1.2&wt=json&json.nl=map&q=%2A%3A%2A&start=0&rows=5&sort=mod_date+desc), and just simply remove the "wt" parameter, then the sort works. BUT the results appear differently, thus making my php code not able to recognize the results I believe. Donovan would know this I think. I am guessing in order for the PHPClient to work, the results must be in a specific structure, which gets messed up as soon as I remove the wt parameter.

Donovan, help me please...

Here is some background what I use your SolrPhpClient for: I have a classifieds website, which uses MySql. But for the searching I am using Solr to search some indexed fields. Then Solr returns an array of ID:numbers (for all matches of the search criteria). Then I use those ID:numbers to find everything in a MySql db and fetch all other information (example is not searchable information).

So simplified: Search -> Solr returns all matches in an array of ID:nrs -> Id:numbers from Solr are the same as the Id numbers in the MySql db, so I can just make a simple match agains every record with the ID matching the ID from the Solr results array.

I don't use Faceting, no boosting, no relevancy or other fancy stuff. I only sort by the latest classified put, and give the option to users to also sort on the cheapest price. Nothing more.

Then I use the "fq" parameter to do queries on different fields in Solr depending on category chosen by users (example "cars" in this case which in my language is "Bilar").

I am really stuck with this problem here... Thanks for all help