Re: Checking for schedule conflicts
От | Ragnar Hafstað |
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Тема | Re: Checking for schedule conflicts |
Дата | |
Msg-id | 1110622413.28805.13.camel@localhost.localdomain обсуждение исходный текст |
Ответ на | Checking for schedule conflicts (Benjamin Smith <lists@benjamindsmith.com>) |
Ответы |
Re: Checking for schedule conflicts
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Список | pgsql-general |
On Sat, 2005-03-12 at 00:13 -0800, Benjamin Smith wrote: > Given the tables defined below, what's the easiest way to check for schedule > conflicts? > > So far, the only way I've come up with is to create a huge, multi-dimensional > array in PHP, with a data element for every minute of all time taken up by > all events, and then check for any of these minutes to be set as I go through > all the records. (ugh!) > > But, how could I do this in the database? > > But I'd like to see something like > "select count(*) FROM events, sched > WHERE sched.date=$date > AND events.id=sched.events_id > ... > GROUP BY date, start<finish and finish<start > HAVING count(*) >1 " > > And here's where I get stumped. You can't group by start or end because we > need to check if they OVERLAP any other records on the same date. > > Ideas? use the OVERLAPS operator ? http://www.postgresql.org/docs/8.0/interactive/functions-datetime.html gnari
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