Re: SQL to Check whether "AN HOUR PERIOD" is between start and end timestamps
От | Alvaro Herrera |
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Тема | Re: SQL to Check whether "AN HOUR PERIOD" is between start and end timestamps |
Дата | |
Msg-id | 20090402135404.GD3163@alvh.no-ip.org обсуждение исходный текст |
Ответ на | Re: SQL to Check whether "AN HOUR PERIOD" is between start and end timestamps (James Kitambara <jameskitambara@yahoo.co.uk>) |
Ответы |
Re: SQL to Check whether "AN HOUR PERIOD" is between start and end timestamps
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Список | pgsql-sql |
James Kitambara wrote: > Dear Srikanth, > You can solve your problem by doing this > > THE SQL IS AS FOLLOWS > ASSUME TIME INTERVAL 2008-12-07 07:59:59 TO 2008-12-07 08:58:59 AND THE TABLE NAME time_interval > > COUNT (*) FROM > (select customer_id, log_session_id, start_ts, end_ts , end_ts-start_ts as "Interval" from time_interval > where end_ts-start_ts >= '1 hour' > and '2008-12-07 07:59:59' between start_ts and end_ts) > AS COUNT ; Another way to phrase the WHERE clause is with the OVERLAPS operator, something like this: WHERE (start_ts, end_ts) OVERLAPS ('2008-12-07 07:59:59', '2008-12-07 08:59:59') What I'm not so sure about is how optimizable this construct is. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc.
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