Question

Is there a way to update only Hour part in a DateTime field?? If not, how do I update the time part in Oracle? I tried this->

update tab_name 
set C_Name=to_date('04/03/2012 00:31:00','MM/DD/YYYY HH:MI:SS AM') 
where C_Name1=10484;  

didn’t work as I’m updating ’00’ in Hour part.

Answer 1

If I knew I wanted to update just one part of the time I’d probably convert to a string with the value I want in the appropriate place, then convert back to a date. Say I wanted the minutes to be “31”:

update tab_name 
set C_Name=
  to_date( 
    to_char(C_Name, 'MM/DD/YYYY HH24:"31":SS'),
    'MM/DD/YYYY HH24:MI:SS'
  ) 
where C_Name1=10484;  

If you want to modify the time portion relative to its current value (to add 2 hours or subtract 3 seconds, for example) then there are some choices for date arithemtic. The Oracle documentation is very good for these things.