zf2 make a join between two different databases

Question

I am trying to make a join between two tables placed in different databases with Zend Framework 2.

The first table is called users and is stored in

Answer 1

Looks like this question was asked a while back, but I seem to have found a good workaround or solution. If you utilize the Zend\Db\Sql\TableIdentifier and Zend\Db\Sq\Expression, you will be able to get around your issue.

public function getSelect(Hierarchy $hierarchy) {
    $select = $this->tableGateway->getSql()->select();
    $select->where(array('level' => $hierarchy()->getId()));
    $select->join(
         array('h' => new TableIdentifier('hierarchies', 'admin')), 
         new Expression('h.id = ?', 'users.idHierarchy', Expression::TYPE_IDENTIFIER), 
         array('hierarchyId' => 'id', 'level' => 'level')
    );
    return $select;
}

I wasn't sure which database your hierarchies table is in so I used 'admin' for now. YOu can replace it with which ever database name you have. See if it works for you, seems to work nicely for me.