Question

Scenario

UDPATE

Please ignore the commented section. After thinking for an alternative, I came up with this:

Let’s say I have

$date = '2012-10-03 13:00:00'

The time interval range is

2012-10-03 12:00:00 to 2012-10-03 14:00:00

Now $date falls between the time range mentioned above. Any ideas on how to compare a date time with a range of date time? I’ve come across functions which compare either just date or just time but not both at the same time. Any help much appreciated.

/*I'm building a school timetable and want to make sure that a room cannot be assigned to two different periods if it is already occupied. I have datetime values of **`2012-10-03 13:00:00`** (the start time of a period. Let's call it **abc** for reference) and **`2012-10-03 13:30:00`** (the end time of a period. Let's call it **xyz** for reference). 

My database table contains columns for room number assigned for a period and the start and end time of that period. Something like this:

    room_no | start_time          | end_time
       5      2012-10-03 13:00:00   2012-10-03 14:30:00

This means for October 3, 2012 room 5 is occupied between 1pm and 2:30pm. So the datetime values that I have (abc & xyz) will have to be assigned to a room other than 5.

I'm at a loss of ideas on how to go about validating this scenario, i.e. make sure that the period with time interval between abc & xyz cannot be assigned room number 5.

Any help would be appreciated. Thanks in advance

PS : I'm not asking for code. I'm looking for ideas on how to proceed with the issue at hand. Also, is there a way a query can be build to return a row if `abc` or `xyz` lie between `start_time` and `end_time` as that would be great and reduce a lot of workload. I could simply use the number of rows returned to validate (if greater than 0, then get the room number and exclude it from the result)*/

Answer 1

if(StartTime - BookingTime < 0 && BookingTime - EndTime < 0)
{
  // Booking time is already taken
}

You can do this in SQL with TIMEDIFF().