How to retrieve missing time intervals

[end3r]

Hi guys,

I have the following problem

select a.id, a.start_date, a.end_date, b.start_date, b.end_date
from interval_1 a,
 interval_2 b
where a.id = b.parent_id

This will generate a solution like:

5 | 01-Apr-2012 08:30:00 | 01-Apr-2012 12:00:00 | 01-Apr-2012 09:30:00 | 01-Apr-2012 10:00:00
5 | 01-Apr-2012 08:30:00 | 01-Apr-2012 12:00:00 | 01-Apr-2012 11:00:00 | 01-Apr-2012 11:15:00

I need to find the intervals not covered, so in this example these would be:

01-Apr-2012 08:30:00 | 01-Apr-2012 09:30:00
01-Apr-2012 10:00:00 | 01-Apr-2012 11:00:00
01-Apr-2012 11:15:00 | 01-Apr-2012 12:00:00

I'm out of ideas.

Please help!

[seslie]

Hello end3r,

I'm finding it rather hard to understand what you mean. What do you mean by "finding intervals not covered"? Do you plan to get the results stated below? I cant seem to get what the problem is. Could you be a little clearer, please?

Regards,

Seslie