Rezervace pokojů

CREATE TABLE IF NOT EXISTS `rezervace` (
`id` int(11) NOT NULL,
  `od` date NOT NULL,
  `do` date NOT NULL,
  `jmeno` varchar(100) COLLATE utf8_czech_ci NOT NULL,
  `prijmeni` varchar(100) COLLATE utf8_czech_ci NOT NULL,
  `apartman` int(11) NOT NULL,
  `telefon` varchar(30) COLLATE utf8_czech_ci NOT NULL,
  `email` varchar(100) COLLATE utf8_czech_ci NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8 COLLATE=utf8_czech_ci;

--
-- Vypisuji data pro tabulku `rezervace`
--

INSERT INTO `rezervace` (`id`, `od`, `do`, `jmeno`, `prijmeni`, `apartman`, `telefon`, `email`) VALUES
(1, '2015-04-20', '2015-04-22', 'Jan', 'Zeleny', 1, '723256703', 'a@b.cz'),
(2, '2015-04-21', '2015-04-24', 'Jan', 'Novak', 2, '123456788', 'aa@bb.cz');

CREATE TABLE IF NOT EXISTS `apartmany` (
`id` int(11) NOT NULL,
  `nazev` varchar(50) COLLATE utf8_czech_ci NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 COLLATE=utf8_czech_ci;

--
-- Vypisuji data pro tabulku `apartmany`
--

INSERT INTO `apartmany` (`id`, `nazev`) VALUES
(1, 'AP1'),
(2, 'AP2'),
(3, 'AP2'),
(4, 'AP3');

SELECT a.id, a.nazev, COUNT(r.apartman) > 0 AS obsazeny
FROM apartmany AS a 
LEFT JOIN rezervace AS r ON a.id = r.apartman AND r.od <= '2015-04-21' AND r.do >= '2015-04-26'
GROUP BY a.id