Re: sql query

From: Arn Klammer <Arn.Klammer_at_austrac.gov.au>
Date: Mon, 02 Apr 2001 21:40:46 -0700
Message-ID: <F001.002DF308.20010402211024@fatcity.com>

It's because Oracle dates are stored as a real number, where the integer portion represents the date and the decimal portion represents the time. This means you can do date arithmetic simply by adding or subtracting numbers to a date, where 1.0 = one day, 2.0 = two days, etc.
This means that, as far as fractions of a day are concerned, 0.5 = half a day = 12 hours, 1/24 = one hour, 1/(24 * 60) = 1 minute and 1/(24 * 3600) = 1 second. In your example, 5/(24*3600) = 5 seconds that are being subtracted from the current date/time.

(This representation is really handy - to convert a date/time to just a date (no time portion), you just have to TRUNC() the date.)
-a>>> ravindra_at_sentica.com 3/4/2001 14:00:20
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found a query to get the time 5 seconds less than the current time asselect to_char(sysdate-5/(24*3600),'dd-mon-yyyy hh24:mi:ss') from dual;I am really not sure as to why 24*3600 is used for.Can anyone tell me why it is used.ThanksRavindra-- Please see the official ORACLE-L FAQ: <A
href="http://www.orafaq.com">http://www.orafaq.com-- Author: Ravindra Basavaraja INET: ravindra_at_sentica.comFat City Network Services -- (858) 538-5051 FAX: (858) 538-5051San Diego, California -- Public Internet access / Mailing

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Received on Mon Apr 02 2001 - 23:40:46 CDT