Can we handle the pre defined exceptions?

Question

Hi people,
I have a simple stored procedure in oracle 9i with following code.
create or replace procedure psam1( no int) is
a number;
b number;
e exception;
v varchar(10);
begin
select sal into a from sample where sno=no;
select count(*) into b from sample where sno=no;
if b>1 then
raise e;
elsif a>1000 then
v:='PASS';
else
v:='FAIL';
end if;
dbms_output.put_line(v);
exception
when e then
raise_application_error(-20002,'MORE THAN ONE RECORD EXISTS');
end;
My question is if i want to handle the exception
'ORA-01422: exact fetch returns more than requested number of rows'.
If my fetch retrieves more than one row then Exception e should be raised.but can we handle those predefined exceptions?.

Answer 1

Hi Vids,
As said already, yes you can.
But there is some misunderstandig in your code. If in fact you do have ORA-01422, you second select will never get executed, since the first one will raise that.
You code could be as simple as this:
create or replace procedure psam1(no int)
is
   a   number;
   v   varchar(10);
begin
   select sal, case sign(sal -1000)
                when 1 then 'PASS'
                else 'FAIL'
                end
     into a, v
     from sample
    where sno = no;
   dbms_output.put_line(v);
exception
   when no_data_found  -- Predefined exception for ORA-00001
   then
      do_some_thing; -- Perhaps, just raise;
   when too_many_rows -- Predefined exception for ORA-01422
   then
      do_another_thing;  -- Perhaps, just raise;
end;As you see ORA-01422 is predefined (TOO_MANY_ROWS), read more about those here [Predefined PL/SQL Exceptions|http://download.oracle.com/docs/cd/B28359_01/appdev.111/b28370/errors.htm#insertedID4]
If you choose just to (re)-raise the exception then you should omit that exception handler.
Regards
Peter