Oracle-L: RE: Week - Date function!

From: Ramasubramanian, Shankar (Cognizant) <RShankar1_at_CHN.COGNIZANT.COM>
Date: Mon, 31 Mar 2003 02:33:34 -0800
Message-ID: <F001.00576127.20030331023334@fatcity.com>

I have found out the reasons. Thanks for your information.

-----Original Message-----
Sent: Monday, March 31, 2003 1:34 PM
To: Multiple recipients of list ORACLE-L

Hi Begun ,

I am very eager to know the reason why 27th Nov is taken as the base for each year. Can you please explain me the reasons. This query is really helpful for me .

Thanks & Regards,
Shankar

-----Original Message-----
Sent: Saturday, March 29, 2003 11:39 AM
To: Multiple recipients of list ORACLE-L

Hello!

Sesi Odury wrote:
> Given a week between (1 - 52) for a particular year can we get all the
> dates within that week. Is there a function to do this in SQL???

Using the simple statement below you can get the first date of the week (according to ISO standard). Then you can either add 6 to get the last day of the week and use ranges for your task or using any 'pivot'-approach (you need 7 rows) you can get all 7 days/dates of the week.

DEFINE yr=1998
DEFINE wk=5

SELECT TRUNC(TO_DATE('2711&yr', 'DDMMYYYY'), 'IYYY') + (&wk - 1) * 7     AS date_from
      , TRUNC(TO_DATE('2711&yr', 'DDMMYYYY'), 'IYYY') + (&wk - 1) * 7 + 6 AS date_to

FROM sys.dual
/

Ranges can be used in case one does not have a possibility to use FBI, for example.

The statement below is a bit more complicated. This one does a simple check and returns nothing in case week number is out of range.

DEFINE yr=1998
DEFINE wk=53

SELECT TRUNC(TO_DATE('2711&yr', 'DDMMYYYY'), 'IYYY') + (&wk - 1) * 7     AS date_from
      , TRUNC(TO_DATE('2711&yr', 'DDMMYYYY'), 'IYYY') + (&wk - 1) * 7 + 6 AS date_to

FROM sys.dual
WHERE TO_NUMBER(

          TO_CHAR(
            TO_DATE('3112&yr', 'DDMMYYYY')
          + DECODE(TO_CHAR(TO_DATE('3112&yr', 'DDMMYYYY'), 'IW')
                  , '01', -7
                        ,  0
            )
          , 'IW'
          )
        ) >= &wk

AND &wk > 0
/

HTH[, if I did not make a mistake].

-- Vladimir Begun The statements and opinions expressed here are my own and do not necessarily represent those of Oracle Corporation. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Vladimir Begun INET: vladimir.begun_at_oracle.com Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).

-- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Ramasubramanian, Shankar (Cognizant) INET: RShankar1_at_CHN.COGNIZANT.COM Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).

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Received on Mon Mar 31 2003 - 04:33:34 CST