Builds the default count query for SearchQuery.
Since SearchQuery always uses GROUP BY, we can default to a subquery. We also add the same conditions as execute() because countQuery() is called first.
Overrides SelectExtender::countQuery
public function countQuery() {
// Clone the inner query.
$inner = clone $this->query;
// Add conditions to query.
$inner
->join('search_dataset', 'd', 'i.sid = d.sid AND i.type = d.type');
$inner
->condition($this->conditions);
// Remove existing fields and expressions, they are not needed for a count
// query.
$fields =& $inner
->getFields();
$fields = array();
$expressions =& $inner
->getExpressions();
$expressions = array();
// Add the sid as the only field and count them as a subquery.
$count = db_select($inner
->fields('i', array(
'sid',
)), NULL, array(
'target' => 'slave',
));
// Add the COUNT() expression.
$count
->addExpression('COUNT(*)');
return $count;
}