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RE: Implicit Date conversion problem

From: Jamadagni, Rajendra <>
Date: Tue, 29 Oct 2002 07:43:50 -0800
Message-ID: <>


Let me point out one thing .... following is the original query ...

Point to consider is that the "commented out where clause" is the same as the one used in the from clause query ... then why does it fail? Tom: according to Oracle, when comparing a varchar2 to a date column, the string does get converted to a date ...

The reason i am asking this I have to explain the developers on why this isn't working. They agree that explicit datatype conversion is a good idea but their managers want to know why ??

(yeah ... sure go ahead pity me ...)

Rajendra Jamadagni MIS, ESPN Inc. Rajendra dot Jamadagni at ESPN dot com
Any opinion expressed here is personal and doesn't reflect that of ESPN Inc.

QOTD: Any clod can have facts, but having an opinion is an art!

-----Original Message-----
Sent: Tuesday, October 29, 2002 10:35 AM To: ''
Cc: Jamadagni, Rajendra


you are forgetting how dates are stored internally vs. how they are displayed by sqlplus.

change your first query to:

select ea1.ep_number, ea1.est_dt, veas.est_dt   from (select a.ep_number, ea.est_dt

          from v_episode_avail_summary_break a, episode_airings ea 
         where a.ep_number = ea.ep_number 
           and ea.est_dt between to_date('20-Dec-2002','dd-mon-yyyy') and
to_date('01-Jan-2003' ,'dd-mon-yyyy')
         group by a.ep_number, ea.est_dt) veas, 
       episode_airings ea1 

where veas.ep_number = ea1.ep_number
  and ea1.est_dt between between to_date('20-Dec-2002','dd-mon-yyyy') and to_date('01-Jan-2003' ,'dd-mon-yyyy')

Your selection was not working properly because you ended up comparing string values with string values.

example: 21-Dec-2002 is not between 20-Dec-2002 and 01-Jan-2003 using string comparison

                    (21 is greater than 20 and 01 both).

hope this helps.

Tom Mercadante
Oracle Certified Professional


Please see the official ORACLE-L FAQ:

Author: Jamadagni, Rajendra

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Received on Tue Oct 29 2002 - 09:43:50 CST

Original text of this message