Refcursor not returning rows when called from non SQL*Plus IDE or other

Question

Hi all,
I have a very weird problem.
We have recently performed a minor upgrade to our oracle database and are now using:
SQL> select * from v$version;
BANNER
Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi
PL/SQL Release 10.2.0.5.0 - Production
CORE    10.2.0.5.0      Production
TNS for Linux: Version 10.2.0.5.0 - Production
NLSRTL Version 10.2.0.5.0 - Production
5 rows selected.We have a crystal report selecting data from a refcursor returned by a stored procedure.
The stored procedure updates data when called as well as returning the refcursor in question.
Observe the following test scenario executed in SQL*Plus:
SQL> create table testtab (teststr varchar2(100));
Table created.
Elapsed: 00:00:00.00
SQL> insert into testtab values ('X');
1 row created.
Elapsed: 00:00:00.00
SQL> create or replace procedure testtabproc (p_listcur in out sys_refcursor)
  2  as
  3  begin
  4 
  5     open p_listcur for
  6        select *
  7          from testtab
  8         where teststr = 'X';
  9 
10 
11     update testtab
12        set teststr = 'Y';
13 
14        commit;
15 
16  end;
17  /
Procedure created.
Elapsed: 00:00:00.00
SQL> declare
  2 
  3  v_list_cur sys_refcursor;
  4 
  5  type t_out_rec is record (teststr varchar2(100) );
  6 
  7 
  8 
  9  v_out_rec t_out_rec;
10 
11  v_rec_count   number := 0;
12  v_count_limit number := 10000;
13 
14  begin
15 
16  dbms_output.put_line('about to call proc');
17
18  testtabproc(v_list_cur);
19 
20  dbms_output.put_line('about to fetch records');
21 
22  fetch v_list_cur into v_out_rec;
23  while v_list_cur%found loop
24     v_rec_count := v_rec_count + 1;
25     if v_rec_count <= v_count_limit then
26       dbms_output.put_line(v_out_rec.teststr);
27     end if;
28  fetch v_list_cur into v_out_rec;
29  end loop;
30  dbms_output.put_line('complete. selected '||v_rec_count||' records.');
31 
32 
33  end;
34  /
about to call proc                                                                                                                 
about to fetch records                                                                                                             
X                                                                                                                                  
complete. selected 1 records.                                                                                                      
PL/SQL procedure successfully completed.
Elapsed: 00:00:00.00
SQL> select * from testtab;
TESTSTR
Y
1 row selected.
Elapsed: 00:00:00.00
SQL> as you can see, the cursor returns data and the table is updated.
now, our problem is with crystal and also when I use the same test case via another IDE like TOAD.
No data is returned from the list but the table is still updated.
We suspect that something is happening that is causing the table to be updated before the refcursor is opened, or at least before the predicates are applied.
has anyone else encountered this problem before?

Answer 1

Tubby wrote:
WhiteHat wrote:
nope - it works from sqlplus itermitantly (i.e. we always get the debug output but the cursor only sometimes fetches the rows).
it is almost as if the commit is being executed before the cursor is opened.
I still havn't been able to reproduce it except with the actual scenario that I am working with...Is the code you are dealing with exactly the same as the skeleton you've posted in your original post? Do you perhaps have a generic exception catcher in there somewhere (perhaps catching and hiding an ORA-01555) when the cursor is being fetched?
Not that i expect it to make any difference, but i'm curious as to why you've declared your cursor as IN / OUT ?
p_listcur in out sys_refcursor
the code structure in the real example is almost identical to that test case I produced - the exception handler is only catering for no_data_found, all other errors should be raised as normal.
edit: sorry I forgot to add - it's in/out because apparently that's what crystal reports needs in order to use the refcursor..... I'm not a crystal guy so I can't be any more specific than that sorry......
Edited by: WhiteHat on Oct 11, 2010 9:34 AM