Re: SQL to Check whether "AN HOUR PERIOD" is between start and end timestamps

From: Richard Huxton <dev@archonet.com>
Subject: Re: [SQL] SQL to Check whether "AN HOUR PERIOD" is between start and end timestamps
To: "Srikanth" <rssrik@yahoo.co.in>
Cc: pgsql-sql@postgresql.org
Date: Tuesday, 17 March, 2009, 8:36 PM

Srikanth wrote:
> Dear all,
>
> I have a table that records User Login Sessions with two timestamp fields. Basically Start of Session and End of a Session (start_ts and end_ts). Each row in the table identifies a session which a customer has used. 
>
> Data from the table (session):
> -----------------------------
>  customer_id | log_session_id  |          start_ts          |           end_ts
> -------------+-----------------+----------------------------+----------------------------
>  1006100716  | 209571229340224 | 15/12/2008 16:53:52.665327 | 15/12/2008 16:58:52.665327
>  1006100789  | 112061228488202 | 05/12/2008 20:13:32.773065 | 09/12/2008 22:59:02.770218
>  1006100888  | 214221233045949 | 27/01/2009 14:15:16.289626 | 27/01/2009 14:58:59.989182
>  1006000008  | 205221236839534 | 12/03/2009 12:02:15.947509 | 12/03/2009 12:07:15.947509
>  1006100825  | 112331229068049 | 12/12/2008 13:17:37.229249 | 12/12/2008 13:56:58.394577
>
>
> The requirement is as follows,
>
> I have to find out how many User Sessions that were present in any given "1 HOUR TIME PERIOD".  A single User Session can span across many days.

SELECT * FROM session WHERE (start_ts,end_ts) OVERLAPS (<start-of-hour>,
<end-of-hour>);

> I tried using wildcards in timestamp '07/01/2009 11:%:%" but in vain.
I tries googling / searching archives without any success either.

I'd have thought OVERLAPS would be mentioned in the date/time handling
sections of the manual.

--
  Richard Huxton
  Archonet Ltd