Self join criteria in symfony

For Example :
SELECT tbl1.id FROM tbl1 a LEFT JOIN tbl1 b ON a.somecolumnname = b.somecolumn ORDER BY a.somecolumn DESC

The criteria would be as follow

$c=new Criteria();
$c->addAlias(‘a’, ‘tbl1’);
$c->addAlias(‘b’, ‘tbl1’);
$c->addSelectColumn(‘b.id’);
$c->addSelectColumn(‘a.tbl1_id’);
$c->addDescendingOrderByColumn(‘a.somecolumn’);
$c->addJoin(‘a.somecolumnname’,’b.somecolumn’,Criteria::LEFT_JOIN); // Specify your criteria LEFT, RIGHT or INNER
$rs = tbl1Peer::doSelect($c);

Thanks Cheers 🙂