TIMESTAMP formatting!!!

Question

Hi All,
My Query is...
I have a table COGNOS_UH with columns which holds history transaction updates
Business_date Date;
Actual_trans number(8);
Update_trans number(8);
UH_STIME timestamp(6);
UH_FTIME timestamp(6);
UH_DURATION Varchar2(30);
if i try to update UH_DURATION column with diff of start_time & finish_time in this format HH : MIN: SS in a procedure using sql statement shown below...it works fine but i get WARNING message as:
Warning(164,42): PLW-07202: bind type would result in conversion away from column type
UPDATE COGNOS_UH SET UH_DURATION= EXTRACT (HOUR from(UH_FTIME - UH_STIME))||' : '||EXTRACT (MINUTE from(UH_FTIME - UH_STIME))||' : '||EXTRACT (SECOND from(UH_FTIME - UH_STIME));
Could you please suggest how can i resolve this issue/is there any better way to compute the same???

Answer 1

This looks like a bug to me. It seems impossible to get the right conversion take place. Whatever you try you get PLW-07202:
michaels>  alter session set plsql_warnings='ENABLE:ALL'
Session altered.
michaels>  create or replace procedure p
as
   myhiredate   emp.hiredate%type;
begin
   update emp set job = to_char (myhiredate);
end;
Procedure created.
michaels>  show error
Errors for PROCEDURE P
LINE/COL ERROR                                                           
5/34     PLW-07202: bind type would result in conversion away from column
         type 
michaels>  select * from v$version
BANNER                                                         
Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - Prod
PL/SQL Release 10.2.0.3.0 - Production                         
CORE     10.2.0.3.0     Production                                     
TNS for 32-bit Windows: Version 10.2.0.3.0 - Production        
NLSRTL Version 10.2.0.3.0 - Production Only workaround that comes to my mind is to make the statement dynamic, but of course I wouldn't do that just because of a compiler warning.