Question

I have a simple calendar on PHP and MySQL, it stores events in a simple format:

id int
name varchar    
start datetime 
end datetime

What I need to do, and can’t find a reliable way to do it, is to “block” certain time slot so that there can’t be any other event in that time window.

What I’m trying to find basically is the mysql query to check if the new selected time frame is occupied:

If I go this way:

SELECT * FROM events WHERE new_event_start => start AND  new_event_end =< end;

It fails to find an event that starts before new_event_start and ends after new_event_end

Any ideas?

Answer 1

This is a logic question, not a language or technology question.

You need to test for several cases:

End of new event is between the beginning and end of blocked period
OR
Beginning of new event is between the beginning and end of blocked period
OR
Beginning of new event is before the beginning of the blocked period and the end is after the end of the blocked period

That will catch all events that would overlap a blocked period.