Message-ID: <4E732FB7.50009@sympatico.ca>
Date: Fri, 16 Sep 2011 07:15:03 -0400
From: Frank Bax <fbax@sympatico.ca>
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To: pgsql-sql@postgresql.org
Subject: Re: Clever way to check overlapping time intervals ?
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On 09/15/11 19:40, Andreas wrote:
> Hi,
> is there a clever way to check overlapping time intervals ?
> An option named n should be taken from date y to y.
> The same name is ok for another interval.
>
> e.g. table : mytab ( d1 date, d2 date, n text, v text )
>
> There should be a constraint to provide no row can have a d1 or d2
> within the interval of another row in case they have the same n.
>
> And no row can have an interval that encloses an existing interval.
>


self join with "OVERLAPS" operator:

select t1.*,t2.* from (select * from mytab) as t1
     full join (select * from mytab) as t2
     where (t1.d1,t1.d2) overlaps (t2.d1,t2.d2)