预订检查空房情况

Question

I'm creating a system for booking rooms. I need to find out the number of available rooms in the date range.

The room should be available at the checkout date.

So far, I've only been able to find out orders within the date range, but even those don't work as they should.

This works 2020-06-27 - 2020-07-05

This does not work 2020-06-28 - 2020-07-05

The goal is to find out the number of free rooms in the date range and then offer them to order.

I read a lot of topics here, but I didn't come up with a solution.

I use PHP and MySQL

-- phpMyAdmin SQL Dump
-- version 4.7.4
-- https://www.phpmyadmin.net/
--
-- Počítač: 127.0.0.1
-- Vytvořeno: Sob 27. čen 2020, 10:24
-- Verze serveru: 10.1.28-MariaDB
-- Verze PHP: 7.2.1

SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO";
SET AUTOCOMMIT = 0;
START TRANSACTION;
SET time_zone = "+00:00";


/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8mb4 */;

--
-- Databáze: `rezervace`
--

-- --------------------------------------------------------

--
-- Struktura tabulky `booking_orders`
--

CREATE TABLE `booking_orders` (
  `id` int(11) NOT NULL,
  `number` int(11) NOT NULL,
  `checkin` date NOT NULL,
  `checkout` date NOT NULL,
  `first_name` varchar(255) COLLATE utf8_czech_ci NOT NULL,
  `last_name` varchar(255) COLLATE utf8_czech_ci NOT NULL,
  `email` varchar(255) COLLATE utf8_czech_ci NOT NULL,
  `phone` varchar(20) COLLATE utf8_czech_ci NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_czech_ci;

--
-- Vypisuji data pro tabulku `booking_orders`
--

INSERT INTO `booking_orders` (`id`, `number`, `checkin`, `checkout`, `first_name`, `last_name`, `email`, `phone`) VALUES
(74, 0, '2020-06-27', '2020-06-28', '', '', '', ''),
(75, 0, '2020-06-27', '2020-06-29', '', '', '', ''),
(76, 0, '2020-06-27', '2020-07-01', '', '', '', ''),
(77, 0, '2020-06-28', '2020-06-29', '', '', '', '');

-- --------------------------------------------------------

--
-- Struktura tabulky `booking_order_room`
--

CREATE TABLE `booking_order_room` (
  `id` int(4) NOT NULL,
  `order_id` int(4) NOT NULL,
  `room_id` int(4) NOT NULL,
  `product_name` varchar(255) COLLATE utf8_czech_ci NOT NULL,
  `quantity` int(3) NOT NULL,
  `person` int(2) NOT NULL,
  `price` varchar(10) COLLATE utf8_czech_ci NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_czech_ci;

--
-- Vypisuji data pro tabulku `booking_order_room`
--

INSERT INTO `booking_order_room` (`id`, `order_id`, `room_id`, `product_name`, `quantity`, `person`, `price`) VALUES
(81, 74, 7, 'Standard', 1, 1, '50'),
(82, 75, 7, 'Standard', 1, 1, '50'),
(83, 76, 7, 'Standard', 1, 1, '50'),
(84, 77, 7, 'Standard', 1, 1, '50');

-- --------------------------------------------------------

--
-- Struktura tabulky `booking_rooms`
--

CREATE TABLE `booking_rooms` (
  `id` int(11) NOT NULL,
  `name` varchar(255) COLLATE utf8_czech_ci NOT NULL,
  `quantity` int(3) NOT NULL,
  `input` varchar(255) COLLATE utf8_czech_ci NOT NULL,
  `price` int(5) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_czech_ci;

--
-- Vypisuji data pro tabulku `booking_rooms`
--

INSERT INTO `booking_rooms` (`id`, `name`, `quantity`, `input`, `price`) VALUES
(7, 'Standard', 2, 'standard1', 50),
(8, 'Deluxe', 4, 'deluxe2', 100);

--
-- Klíče pro exportované tabulky
--

--
-- Klíče pro tabulku `booking_orders`
--
ALTER TABLE `booking_orders`
  ADD PRIMARY KEY (`id`);

--
-- Klíče pro tabulku `booking_order_room`
--
ALTER TABLE `booking_order_room`
  ADD PRIMARY KEY (`id`);

--
-- Klíče pro tabulku `booking_rooms`
--
ALTER TABLE `booking_rooms`
  ADD PRIMARY KEY (`id`);

--
-- AUTO_INCREMENT pro tabulky
--

--
-- AUTO_INCREMENT pro tabulku `booking_orders`
--
ALTER TABLE `booking_orders`
  MODIFY `id` int(11) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=79;

--
-- AUTO_INCREMENT pro tabulku `booking_order_room`
--
ALTER TABLE `booking_order_room`
  MODIFY `id` int(4) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=85;

--
-- AUTO_INCREMENT pro tabulku `booking_rooms`
--
ALTER TABLE `booking_rooms`
  MODIFY `id` int(11) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=9;
COMMIT;

http://sqlfiddle.com/#!9/bfbabe/1

SELECT checkin, checkout, r.name as name, SUM(i.quantity) as qty 
FROM booking_orders o
LEFT JOIN booking_order_room i on o.id = i.order_id
LEFT JOIN booking_rooms r on i.room_id = r.id
WHERE (checkin >= '2020-06-28' and checkout <= '2020-07-05')
OR (checkin <= '2020-06-28' and checkout >= '2020-07-05')
GROUP BY i.room_id, o.id

Answer 1

I enclose the solution that I finally used. It could probably be done differently.

DROP TABLE IF EXISTS t1;

CREATE TEMPORARY TABLE t1 as (
SELECT r.name as name, r.id, sum(i.quantity) as qty
FROM booking_orders o
LEFT JOIN booking_order_room i on o.id = i.order_id
LEFT JOIN booking_rooms r on i.room_id = r.id
where
(checkin<'2020-07-17' and checkout>='2020-07-17') -- overlap at the end
OR (checkin<='2020-07-15' and checkout>'2020-07-15') -- overlap at the start
OR (checkin>='2020-07-15' and checkout<='2020-07-17') -- complete overlap
GROUP BY r.id
);

SELECT br.name as name, br.quantity as quantity, br.input as input, br. price as price, t1.qty 
FROM booking_rooms br
LEFT JOIN t1 ON t1.id = br.room_id
ORDER BY br.name DESC