To_date function working correctly?

Question

Hi Guys,
Trying to get dates from the table where the date is less than 100 AD but its not working correctly. Could you please comment where Im going wrong?
Thanks,
St
select plan_1_date from TR_PLANNED_EVENT where plan_1_date < to_date('100AD','YYYAD')

Answer 1

Saurabh T wrote:
You should compare similar date formats.Dates don't have formats.
>
Try below to make date formats similar:
select plan_1_date from TR_PLANNED_EVENT where to_char(plan_1_date, 'DD-MON-YYYY') < to_char(to_date('100AD','YYYAD'), 'DD-MON-YYYY')
This is called string comparison and is not comparing dates and will produce the wrong answer like this -
SQL> with mytable as
  2    (
  3    select date '2010-01-28' + level mydate from dual
  4    connect by level <= 5
  5    )
  6  select mydate, sysdate from mytable;
MYDATE     SYSDATE
01/29/2010 07/13/2010
01/30/2010 07/13/2010
01/31/2010 07/13/2010
02/01/2010 07/13/2010
02/02/2010 07/13/2010
SQL> edi
Wrote file afiedt.sql
  1  with mytable as
  2    (
  3    select date '2010-01-28' + level mydate from dual
  4    connect by level <= 5
  5    )
  6  select mydate, sysdate from mytable
  7* where to_char(mydate, 'DD-MON-YYYY') < to_char(sysdate, 'DD-MON-YYYY')
SQL> /
MYDATE     SYSDATE
02/01/2010 07/13/2010
02/02/2010 07/13/2010
Hope it helps.It is very unhelpful and incorrect.
Edited by: 3360 on Jul 13, 2010 8:08 AM