Question

We are building an Reservation booking system. There are three modules

1. Customers
2. Rooms
3. Bookings

A customer can book one or many rooms and for varying dates. While booking a room(s) i want to search for which rooms are available to be booked between date A and date B.

Tables ( likely solution)
customers(id, name, …..)
rooms(id, roomNo, roomType, ….)
bookings(id, room_id, fromDate, toDate)

Presently i have the tables like this

CREATE TABLE IF NOT EXISTS `bookings` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `checkin` datetime NOT NULL,
  `checkout` datetime NOT NULL,
  `advance` int(11) NOT NULL,
  `amount` int(11) NOT NULL,
  `booking_details_id` int(11) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;


CREATE TABLE IF NOT EXISTS `bookings_rooms` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `booking_id` int(11) NOT NULL,
  `room_id` int(11) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ;


CREATE TABLE IF NOT EXISTS `customers` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) NOT NULL,
  `age` int(11) NOT NULL,
  `address` varchar(255) NOT NULL,
  `nationality_id` int(11) NOT NULL,
  `mobile` int(20) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;

CREATE TABLE IF NOT EXISTS `rooms` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `number` int(4) NOT NULL,
  `category_id` int(11) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ;

Need help to design the database and which is a better approach.

Answer 1

These schema structures already allow you to find the free rooms between two dates.

The following query will check if rooms booked before start-time will be free before start-time or, for those ones booked after, it checks if they’re checkin is following end-date too.

select *
from rooms r
where id not in (
        select room_id
        from bookings_rooms br
            join bookings b on (br.booking_id=b.id)
        where (checkin < :dateA and checkout > :dateA)
            or (checkin > :dateA and checkin < :dateB)
    )