Drupal Search API custom search field order

Question

am using search api views module to search my apache Solr Search engine. I would like to have a custom order for the returned results. I would like the jq_articles results to appear first, then books, then mydocuments.

How can I have this customer order (with is neither ASC or DESC) for my returned results?

I mean I need something like $query->orderby('jq_articles, 'books', 'mydocuments');

This is how my query_alter looks at the time being:

<?php
function mymodule_search_api_query_alter(SearchApiQueryInterface $query) {
    $filters = &$query->getFilter()->getFilters();
    foreach ($filters as $i => $filter) {
        $condition="";
        $finalfilters=&$filter->getFilters();
        foreach($finalfilters as $z => $singlefilter){
                    if($singlefilter[0]=='type') {
                         $condition=$singlefilter[1];
                         unset($finalfilters[$z]);
                    }
         }
    }
          $filter = $query->createFilter('OR');
switch($condition) {
            case 'journals':
              $filter->condition('type', 'jq_articles');
              break;
            case 'books':
                $filter->condition('type', 'books');
                break;
            case 'mydocuments':
            $filter->condition('type', 'mydocuments');
            default:
            $filter->condition('type', 'mydocuments');
            $filter->condition('type', 'books');
            $filter->condition('type', 'jq_articles');
            break;
}
          $query->filter($filter);
}
?>

Answer 1

You can do this by adding the following in hook_search_api_query_alter():

$query->sort('jq_articles', 'DESC');

If you want to sort by multiple fields, you should do like this:

$query->sort('field1', 'DESC');
$query->sort('field2', 'ASC');

Answer 2

As Update for Drupal 8/9 You can always use hook_search_api_query_alter

If you want to unset or re-order of sort criteria you can use getSorts():

//$sorts becomes reference to $query->sorts
$sorts = &$query->getSorts();
//by example remove a sort criteria
  unset( $sorts['created']);