Time redunduncy

[tomex]

hello guys..
I have trouble on what should i do. i am making a system where in a student may reserve a station with a start time and end time. my problem is what should i do so that the time entered in a station number may not conflict with a new entered time on the same station ex.


ResNo .......... STATION........ . STARTTIME ......... ENDTIME
1 ............... ... 1.............. .......2:00.... ............... .....3:00
2 ............... .....1*........ .......... 2:30*.......... ............ 3:00 *

*how would i know that it would not conflict on the first resrvation

thanks guys i really appreciate your help right now..=)

its online i'm using php and mySQL as my DBMS

[Atli]

Hey.

You can use the BETWEEN ... AND ... operator to figure that out.

A select statement using two of those, checking whether the start and the end were within another range, should work.
[code=sql]
SELECT ...
WHERE '02:30' BETWEEN `start` AND `end`
AND '03:00' BETWEEN `start` AND `end`
[/code]
Something like that would give you a list of all rows that collided with your given range. If this came up empty, you would be OK to reserve the new range.