db_or() returns a SelectQuery-object In my module, I was trying to make use of db_or() in this way...

$filterSparten = db_select($this-&gt;tbl_hat_sparte, 'hs')
  -&gt;fields('hs', array('hat_AID'));

$or = db_or();

foreach($_GET['tags'] as $tag) {
  $or-&gt;condition('hat_KID', $tag);
 }

 $filterSparten-&gt;condition($or)
  -&gt;execute()
  -&gt;fetchAssoc();


...which, unfortunately, only returns a SelectQuery-object:

SelectQuery Object
(
    [fields:protected] =&gt; Array
        (
            [hat_AID] =&gt; Array
                (...


Why doesn't my code return a fetched results-object? I have compared it several times with the examples on the Drupal-pages, but I can't help myself with it.
Assuming an unchanged core codebase, and assuming you mean that your final line is returning a SelectQuery (not the db_or(), which returns a DatabaseCondition), the only way you could be seeing a SelectQuery is if you're inspecting the wrong variable, i.e. $filterSparten. The query will remain a query, you need to assign the results to something else:

$results = $filterSparten-&gt;condition($or)
  -&gt;execute()
  -&gt;fetchAssoc();


Inspecting $results should give you what you're expecting.