SQL / PHP如何验证日期是否在日期范围之间？

Question

I currently have a bookings and rooms table:

bookings table

rooms table

2

I am trying to make a search room sql query that takes into account the current check in and check out date on a room.I do not know how to implement a WHERE condition to check for rooms both with and without existing bookings record. and if a booking record does exist on how can i validate a user input's check in and check out dates so that the query will not output rooms with bookings that clashes with the users input date range

This is my sql so far:

$sql = "SELECT rooms.rid, beds, orientation, price FROM rooms JOIN bookings ON rooms.rid = bookings.rid
WHERE (beds = $nOfBeds)
AND ($cInDate < checkin AND $cOutDate <= checkin)
OR ($cInDate > checkout AND $cOutDate >= checkout)";
if ($rOrientation != "") {
$sql .= " AND orientation = '$rOrientation'";
}

right now it is only outputting rooms that has an existing booking and not outputting other rooms that meets the number of beds parameter but without existing bookings.

Answer 1

BETWEEN Operator with Date Value Example

http://www.w3schools.com/sql/trysql.asp?filename=trysql_select_between_date&ss=-1

AND ( checkin BETWEEN $cInDate AND $cOutDate )