$dbSelect = $this->getConnection()->createQueryBuilder()
	->select('e.*, (' . $this->_credentialColumn . ' = ' . str_replace('?', '"' . $this->_credential . '"', $this->_credentialTreatment) . ') AS zend_auth_credential_match')
	->from($this->_tableName, 'e')
	->where('e.' . $this->_identityColumn . ' = ?1')
	->setParameter(1, $this->_identity);


getDQL()
---
SELECT e.*, (password = SHA1("changeme")) AS zend_auth_credential_match FROM Application_Model_Users e WHERE e.username = ?1

Exception
--
Message: [Syntax Error] line 0, col 22: Error: Expected Doctrine\ORM\Query\Lexer::T_CLOSE_PARENTHESIS, got '='