How to display output parameters in storedprocedures in front end?

Question

hi all ,thank you for all the support.
Now i want your help .Here below i have given the general format of stored procedure we are using in our application . In procedure we are catching the exception and assigning to an output variable P_STATUS .
If any exception occurs ,How we display this caught exception from front end that means how we display the exception in front end .We are using VB.NET and VS 2005 and Oracle 9i for development.
CREATE OR REPLACE PROCEDURE SELECTINTERVALS
P_MINVAL INTEGER,
P_MAXVAL INTEGER,
P_INTERVAL     INTEGER,
P_USERID VARCHAR2,
P_STATUS OUT VARCHAR2
AS
BEGIN
          SELECT STATEMENT or INSERT STATEMENT     
EXCEPTION
          WHEN OTHERS THEN
          ROLLBACK;
          P_STATUS:=SQLERRM;
END;
If anybody knows, please help me
thanks & regards

Answer 1

Both methods are wrong. Returning error/exit codes for the reasons I've stated above.
As for handling the exception... If you want to propagate the exception, then DO NOT CHANGE IT INTO A MEANINGLESS USER EXCEPTION!
This is useless:
WHEN OTHERS THEN
ROLLBACK;
P_STATUS:=SQLERRM;
RAISE_APPLICATION_ERROR(-20011, SQLERRM);
Why it is meaningless? Because the caller now has to parse the error message to determine just what the actual root exception was... as the root exception number has been replaced with a meaningless number.
This is meaningful and (almost) correct:
[pre]
when OTHERS then
rollback;
raise; -- re-raise the exception
PS. It makes better sense to trap the actual exception like no data found, duplicate PK violations, etc... it seldom makes sense to trap all other exceptions and then do something like a rollback.