$qb = $this->createQueryBuilder('u');
			$qb->select(array('u,c'))
				->innerJoin('u.Entities\Client','c');
			if (!preg_match('/^\d+$/', $client_id)){
				$qb->where($qb->expr()->like('u.client_id',':client_id'));
				$client_id = '%'.$client_id.'%';
			} else {
				$qb->where('u.client_id = :client_id');
			}
			$qb->andWhere('u.username = :username')
				->andWhere('u.password = :password')
				->setParameters(
					array(
						'client_id' => $client_id,
						'username' => $username,
						'password' => $password
					)
			);