Need help in Cursor exception

Question

Hi,
I have a small code with implicit cursor to fetch rows from table unreadable_cards and then for each value fetched I lookup another table card_acnt for some values and update data in unreadable cards table. The code is as below
declare
v1 number;
begin
for v1 in (select engravedid from unreadable_cards where case_resolved=1)
loop
update unreadable_cards set serial_number = (select serial_number from card_account
where ticketid = v1.engravedid)
where engravedid = v1.engravedid;
update unreadable_cards set case_resolved=2
where case_resolved=1
and serial_number is not null;
end loop;
exception
when no_data_found then
update unreadable_cards set case_resolved=22
where ticketid = v1.engravedid;
when too_many_rows then
update unreadable_cards set case_resolved=23
where ticketid = v1.engravedid;
when others then
update unreadable_cards set case_resolved=24
where ticketid = v1.engravedid;
end;
Here I have problem writing values to the table as this error pops up for every reference to V1 in exception
PLS-00487: Invalid reference to variable 'V1'
I need to be able to raise all three exceptions within the loop so that v1 can be referenced and loop does not exit on encountering the exception and completes for every row fetched by cursor, so that I can track the status of each record on the basis of case_resolved value.
Any help would be highly appreciated
Thanks
Saurabh

Answer 1

Let me get that out of me.. I don't like your code
First thing you need to know is, you are not going to hit NO_DATA_FOUND exception in a UPDATE statement. If a update did not modify any row it will not raise NO_DATA_FOUND exception. Check this out
SQL> begin
  2    update emp set sal = sal+ 10 where 1=2;
  3  end;
  4  /
PL/SQL procedure successfully completed.
No exception there. So that is one thing you need to look at.
Second thing I don't like the way you have used WHEN OTHERS exception. What are the exception you are looking at? You should not be having a when others without RAISE. It a bug in the code. You need to fix that.
Assuming your logic behind assigning CASE_RESOLVED is like this.
CASE_RESOLVED = 2   means you have found an exact match for your UNREADABLE_CARDS.ENGRAVEDID in CARD_ACCOUNT.TICKETID
CASE_RESOLVED = 22 means you don't have a match for your UNREADABLE_CARDS.ENGRAVEDID in CARD_ACCOUNT.TICKETID
CASE_RESOLVED = 23 means you have multiple match for your UNREADABLE_CARDS.ENGRAVEDID in CARD_ACCOUNT.TICKETID
CASE_RESOLVED = 24 This does not make any sense. You need to drop this part.
You can do this, You don't need all that PL/SQL. Just a simple SQL like this will do.
merge into unreadable_cards x
using (
        select a.engravedid
             , max(b.serial_number) serial_number
             , case when count(b.serial_number) = 1 then 2
                    when count(b.serial_number) = 0 then 22
                    when count(b.serial_number) > 1 then 23
               end case_resolved
          from unreadable_cards a
          left
          join card_account b
            on a.engravedid = b.eticketid
         where a.case_resolved = 1
         group
            by a.engravedid
      ) y
   on (
        x.engravedid = y.engravedid
when matched then
update set x.serial_number = nvl(y.serial_number, x.serial_number)
          , x.case_resolved = y.case_resolved;
Above is a untested code. But should work. If any minor error fix it and you should be good to go.