Collection does not exist after update of session state

Question

Attempting to leverage sample application code from Knowledge Testing 1.0 using apex v3.00 and getting ORA-20102: Application collection QUESTIONS does not exist
Note that the error is thrown in a cursor loop over that very collection (see bolded text below)
Can anyone shed some light on the subject?
Thx,
Derek
SFFD
procedure get_question
is
  c             pls_integer := 0;I NUMBER;
  l_question    pls_integer := 0;
--DEBUG
  log_root number;
--/DEBUG
begin
--DEBUG
    begin
      select max(log_id) into log_root from fdrpts.log_entries where routine='QUIZ';
       exception when no_data_found then
           log_root:= fdrpts.log.add('INFO','QUIZ','Testing quiz functions');
       end;
    IF LOG_ROOT IS NULL THEN log_root:= fdrpts.log.add('INFO','QUIZ','Testing quiz functions'); END IF;
--/DEBUG
    l_question := nvl(nv('KT_QUESTION'),1);
--DEBUG
    log_root := fdrpts.log.add('INFO','QUIZ.GET_QUESTION','quiz.get_question('||to_char(l_question)||')',LOG_ROOT);
SELECT COUNT(*) INTO i FROM APEX_COLLECTIONS WHERE COLLECTION_NAME='QUESTIONS';
*fdrpts.log.add('INFO','QUIZ.GET_QUESTION',TO_CHAR(i)||' QUESTIONS IN TEST QUEUE',LOG_ROOT);*
--/DEBUG
    if l_question > nvl(nv('KT_QUESTION_COUNT'),1) THEN -- wrap to beginning of test, page logic will handle quit.
--DEBUG
       fdrpts.log.add('INFO','QUIZ.GET_QUESTION','KT_QUESTION ('||L_QUESTION||') > KT_QUESTION_COUNT ('||nvl(nv('KT_QUESTION_COUNT'),1)||') WRAPPING AND SETTING STATUS TO ''REVIEW''',LOG_ROOT);
--/DEBUG
       wwv_flow.update_cache_with_write('KT_TEST_STATUS','REVIEW');
       wwv_flow.update_cache_with_write('KT_QUESTION',1);
       l_question:=1;
    end if;
    *for c1 in (*
    SELECT
      SEQ_ID,
      c001 q_number,
      c004 qtype,
      c005 question,
      c006 image,
      c007 question_footer,
      c008 question_header,
      c009 answer,
      trim(c010) WRONG1,
      trim(c011) WRONG2,
      trim(c012) wrong3,
      trim(c013) wrong4,
      c014 correct_answer,
      c015 w1,
      c016 w2,
      c017 w3,
      c018 w4,
      c020 answer_given,
      c021 get_time,
      c022 post_time
    *FROM APEX_collections*
    *WHERE collection_name = 'QUESTIONS'*
    order by c002
    *) loop* -- NOTE: the order by c002
        c := c + 1;
--DEBUG
fdrpts.log.add('INFO','QUIZ.GET_QUESTION','quiz.get_question SCANNING '||TO_CHAR(C),LOG_ROOT);
--/DEBUG
        if c = l_question then -- this is the nth question in test's ordering method
            wwv_flow.update_cache_with_write('KT_QUESTION_TEXT',htf.escape_sc(c1.question));
            wwv_flow.update_cache_with_write('KT_QUESTION_FOOTER',htf.escape_sc(c1.question_footer));
            wwv_flow.update_cache_with_write('KT_QUESTION_HEADER',htf.escape_sc(c1.question_header));
            wwv_flow.update_cache_with_write('KT_QTYPE',nvl(c1.qtype,'PICTURE'));
            wwv_flow.update_cache_with_write('KT_SELECTION',c1.answer_given);
            wwv_flow.update_cache_with_write('KT_IMAGE','<img src="'||
                replace(replace(replace(c1.image,
                   '#WORKSPACE_IMAGES'||'#',
                   v('WORKSPACE_IMAGES')),
                   '#APP_IMAGES'||'#',
                   v('APP_IMAGES')),
                   '#IMAGE_PREFIX'||'#',
                   v('IMAGE_PREFIX'))||
                '" alt="picture" />');
            wwv_flow.update_cache_with_write('KT_COLLECTION_SEQ_ID',c1.SEQ_ID);
--DEBUG
fdrpts.log.add('INFO','QUIZ.GET_QUESTION','quiz.get_question SESSION VARS SET',LOG_ROOT);
--/DEBUG
            if c1.correct_answer = 1 then
               wwv_flow.update_cache_with_write('KT_CORRECT','1');
               wwv_flow.update_cache_with_write('KT_LABEL1',c1.answer);
               wwv_flow.update_cache_with_write('KT_LABEL2',c1.wrong1);
               wwv_flow.update_cache_with_write('KT_LABEL3',c1.wrong2);
               wwv_flow.update_cache_with_write('KT_LABEL4',c1.wrong3);
               wwv_flow.update_cache_with_write('KT_LABEL5',c1.wrong4);
            elsif c1.correct_answer = 2 then
               wwv_flow.update_cache_with_write('KT_CORRECT','2');
               wwv_flow.update_cache_with_write('KT_LABEL2',c1.answer);
               wwv_flow.update_cache_with_write('KT_LABEL1',c1.wrong1);
               wwv_flow.update_cache_with_write('KT_LABEL3',c1.wrong2);
               wwv_flow.update_cache_with_write('KT_LABEL4',c1.wrong3);
               wwv_flow.update_cache_with_write('KT_LABEL5',c1.wrong4);
            elsif c1.correct_answer = 3 then
               wwv_flow.update_cache_with_write('KT_CORRECT','3');
               wwv_flow.update_cache_with_write('KT_LABEL3',c1.answer);
               wwv_flow.update_cache_with_write('KT_LABEL1',c1.wrong1);
               wwv_flow.update_cache_with_write('KT_LABEL2',c1.wrong2);
               wwv_flow.update_cache_with_write('KT_LABEL4',c1.wrong3);
               wwv_flow.update_cache_with_write('KT_LABEL5',c1.wrong4);
            elsif c1.correct_answer = 4 then
               wwv_flow.update_cache_with_write('KT_CORRECT','4');
               wwv_flow.update_cache_with_write('KT_LABEL4',c1.answer);
               wwv_flow.update_cache_with_write('KT_LABEL1',c1.wrong1);
               wwv_flow.update_cache_with_write('KT_LABEL2',c1.wrong2);
               wwv_flow.update_cache_with_write('KT_LABEL3',c1.wrong3);
               wwv_flow.update_cache_with_write('KT_LABEL5',c1.wrong4);
            else
               wwv_flow.update_cache_with_write('KT_CORRECT','5');
               wwv_flow.update_cache_with_write('KT_LABEL5',c1.answer);
               wwv_flow.update_cache_with_write('KT_LABEL1',c1.wrong1);
               wwv_flow.update_cache_with_write('KT_LABEL2',c1.wrong2);
               wwv_flow.update_cache_with_write('KT_LABEL3',c1.wrong3);
               wwv_flow.update_cache_with_write('KT_LABEL4',c1.wrong4);
            end if;
--DEBUG
fdrpts.log.add('INFO','QUIZ.GET_QUESTION','quiz.get_question LABELS SET',LOG_ROOT);
*fdrpts.log.add('INFO','QUIZ.GET_QUESTION','GET_TIME='||to_char(sysdate-nvl((to_date(c1.post_time,'YYYYMMDDHH24MISS')-to_date(c1.get_time,'YYYYMMDDHH24MISS')),0),'YYYYMMDDHH24MISS'),LOG_ROOT);*
--/DEBUG
            -- set question generation time  *THIS IS THE OFFENDING STATEMENT*
            APEX_COLLECTION.UPDATE_MEMBER_ATTRIBUTE(
              p_collection_name       => 'QUESTIONS',
              p_seq                   => c1.seq_id,
              p_attr_number           => 21,  --GET_TIME
              p_attr_value            => to_char(sysdate-nvl((to_date(c1.post_time,'YYYYMMDDHH24MISS')-to_date(c1.get_time,'YYYYMMDDHH24MISS')),0),'YYYYMMDDHH24MISS'));
*fdrpts.log.add('INFO','QUIZ.GET_QUESTION','quiz.get_question READY TO EXIT',LOG_ROOT);*
            exit;
        end if;
    *end loop;*
--DEBUG
fdrpts.log.add('INFO','QUIZ.GET_QUESTION','quiz.get_question EXIT',LOG_ROOT);
--/DEBUG
end get_question;LOGS
    *LOG_ID          DTTM                       ROUTINE                                     TEXT*
   7014853 04/23/09 11:40:57 QUIZ                                 TEST 14
   7014854 04/23/09 11:41:22 QUIZ.INIT_TEST                 quiz.init_test(2,918615994152352,'DEREK')
   7014855 04/23/09 11:41:22 QUIZ.INIT_TEST                 4/5 QUESTIONS RANDOMIZED
   7014856 04/23/09 11:41:22 QUIZ.INIT_TEST                 RANDOM QUEUE CREATED 5 ENTRIES
   7014857 04/23/09 11:41:22 QUIZ.INIT_TEST                 GROUP 2
   7014858 04/23/09 11:41:22 QUIZ.INIT_TEST                 4 QUESTIONS IN TEST QUEUE
   7014859 04/23/09 11:41:22 QUIZ.INIT_TEST                 SESSION VARS SET
   7014860 04/23/09 11:41:23 QUIZ.GET_QUESTION              quiz.get_question(1)
   7014861 04/23/09 11:41:23 QUIZ.GET_QUESTION              4 QUESTIONS IN TEST QUEUE
   7014862 04/23/09 11:41:23 QUIZ.GET_QUESTION              quiz.get_question SCANNING 1
   7014863 04/23/09 11:41:23 QUIZ.GET_QUESTION              quiz.get_question SESSION VARS SET
   7014864 04/23/09 11:41:23 QUIZ.GET_QUESTION              quiz.get_question LABELS SET
   *7014865 04/23/09 11:41:23 QUIZ.GET_QUESTION              GET_TIME=20090423114123*
13 rows selected.Edited by: derek on Apr 23, 2009 1:43 PM
Edited by: derek on Apr 23, 2009 2:06 PM

Answer 1

Hi Tyson,
If you look closely you will see that the routine already has access to the collection (which is, in fact, instantiated in a different procedure).
The routine has a debug statement to count and log the number of collection members; that statement reports 4 members in the collection.
Then the routine opens a cursor loop over that collection, calcs and sets some session variables and attempts to update the collection.
It is at this point (in the midst of the cursor loop over the same collection) that the collection does not exists is thrown.
Does it not follow that if the cursor loop has entered its first iteration, then the collection exists? How then does it cease to exist during the cursor loop (absent a call to one of apex_collection.delete_ methods)?
Derek
SFFD