Help find the Last run date from previous month

Question

Hi all
I am stuck trying to find the Last Run Date from the previous month.
select distinct(date_ran) from TABLE X where date_ran like '%/11-%' order by date_ran desc gives
"03/30/11-06:19
"03/25/11-03:01
"03/24/11-03:00
"03/23/11-03:00
"03/22/11-03:00
"03/21/11-03:00
"03/18/11-03:00
"03/17/11-00:00
"03/16/11-06:31
"02/15/11-07:42
"02/15/11-06:00
"02/14/11-08:19
Here the result I am trying to acheive is 02/15/11-07:42 ;Note the column date_ran is a VARCHAR2(255) and not a TIMESTAMP
I tried
select ADD_MONTHS(to_date(max(date_ran), 'MM/DD/YYYY-HH24:MI'),-1)
from daily_tests_a
where date_ran like '%/11-%'
order by date_ran desc
which returns 2/28/0011 6:19:00 AM and that is not the result I am looking for
Regards
SMK

Answer 1

Welcome to the forum!
user2931503 wrote:
Hi all
I am stuck trying to find the Last Run Date from the previous month.
select distinct(date_ran) from TABLE X where date_ran like '%/11-%' order by date_ran desc gives
"03/30/11-06:19
"03/25/11-03:01
"03/24/11-03:00
"03/23/11-03:00
"03/22/11-03:00
"03/21/11-03:00
"03/18/11-03:00
"03/17/11-00:00
"03/16/11-06:31
"02/15/11-07:42
"02/15/11-06:00
"02/14/11-08:19
Here the result I am trying to acheive is 02/15/11-07:42 ;Note the column date_ran is a VARCHAR2(255) and not a TIMESTAMPThat's a very bad idea. Points in time should always be stored in DATE (or maybe TIMESTAMP) columns. If not, you're going to waste resources converting them to DATEs whenever you need them to behave like DATEs, and risk run-time errors because of bad data.
Normally, the "previous" month means the month before the current month. In April, the previous month is March.
By "previous" month, do you mean the 2nd latest month in the table? That is, this data contains data from February and March, 2011; March 2011 is the latest of those months, February 2011 is the next-to-last, and so is that why you want a date from February?
I tried
select ADD_MONTHS(to_date(max(date_ran), 'MM/DD/YYYY-HH24:MI'),-1)
from daily_tests_a
where date_ran like '%/11-%'
order by date_ran desc
which returns 2/28/0011 6:19:00 AM and that is not the result I am looking for
Regards
SMKTry this:
WITH   got_real_date   AS
     SELECT     TO_DATE ( SUBSTR (date_ran, 1, 14)
               , 'MM/DD/RR-HH24:MI'
               )     AS real_date
     FROM     table_x
--     WHERE     ...     -- If you need any filtering, put it here
SELECT     TO_CHAR ( MAX (real_date)
          , 'MM/DD/RR-HH24:MI'
          )     AS last_date
FROM    got_month_num
WHERE     real_date     < (
                           SELECT  TRUNC (MAX (real_date), 'MONTH')
                     FROM    got_real_date
;Edited by: Frank Kulash on Apr 5, 2011 3:59 PM