To be safe, you may want to do something like this.
Suppose you have a table called CRTEST with data that looks like:
CUSNO CUSNAME CRDATE
1 SMITH 02/21/2099
2 JONES 05/15/2099
3 JOHNSON 08/01/2099
And you know those dates are 1000 years too large.
I 'd do this:
UPDATE CRTEST
SET CRDATE = CRDATE - (CRDATE - TO_DATE(TO_CHAR(CRDATE, 'MM/DD ')|| '/ '||(TO_CHAR(C
RDATE, 'YYYY ')-1000)||to_char(crdate, 'HH24:MI:SS '), 'MM/DD/YYYY HH24:MI:SS '))
Since Oracle does date calculation on days, and years can be somewhat more difficult to precisely define, particularly over a 1,000 years, I wrote the above to force Oracle to do the date arithmetic.
So, what that ugly beast does is it picks apart the date, sets aside the MM/DD portion and the HH24:MI:SS portion, then it subtracts 1000 from the YYYY, and glues it back together, then subtracts that from the original. That gives the difference, and that 's what it subtracts from the original.
I think it should work, and it should preserve the timestamps.
Hope that helps,
-Mark
-- --Original Message-- --
From: Barbara Baker [mailto:barbarabbaker@(protected)]
Sent: Tuesday, March 23, 2004 3:01 PM
To: oracle-l@(protected)
Subject: update year in date column
OK, I 'm just going to bite the bullet and claim total
ignorance here and see if someone takes pity on me :(
(sad face a nice touch, eh?)
Someone has accidently updated 378 records in the
customer table. The date changed from 1999 to 2099.
I need to change just the year back to 1999 for these
records. (I 'd like to keep the time stamp, if
possible. The month and day are correct.) I looked
on metalink, google, and asktom. Some nice examples,
but not what I really need.
Thought I 'd be clever and subtract 1000 from the date.
This works, but I don 't know how to get it formatted
back into a date.
I 'd prefer just sqlplus, but will use pl/sql if
necessary.
Here 's what I 've done so far:
(solaris 9 oracle 9.2.0.4)
