Разные SQL-запросы

SELECT contract.id, contract.title, contract.comment, contract.STATUS, contract_tariff.tpid, contract_tariff.date1, contract_tariff.date2
FROM contract
	LEFT JOIN contract_tariff ON contract_tariff.cid=contract.id
WHERE
	(
		contract.STATUS=0
	)
	AND
	(
		(
			contract_tariff.tpid IS NULL
		)
		OR
		(
			(contract_tariff.date1 IS NOT NULL AND contract_tariff.date1 > now() ) OR (contract_tariff.date2 IS NOT NULL AND contract_tariff.date2 < now() )
		)
	)