Get three previous records of the current record in an Oracle Form

Question

Hi,
I need to get three previous records of the current record in an Oracle Form
Sorry for the lengthy explanation:
I have a table name: ARCHIVE_DATA with column name: coll_time and its data type DATE.
SQL> SELECT COLL_TIME FROM ARCHIVE_DATA;
COLL_TIME
12-AUG-05
12-AUG-05
12-AUG-05
12-AUG-05
12-AUG-05
12-AUG-05
12-AUG-05
12-AUG-05
12-AUG-05
12-AUG-05
10 rows selected.
SQL> select to_char(coll_time,'dd-mon-yyyy:HH:MI:SS') from ARCHIVE_DATA;
TO_CHAR(COLL_TIME)
12-aug-2005:02:42:00
12-aug-2005:02:43:00
12-aug-2005:02:44:00
12-aug-2005:02:45:00
12-aug-2005:02:46:00
12-aug-2005:02:47:00
12-aug-2005:02:48:00
12-aug-2005:02:49:00
12-aug-2005:02:50:00
12-aug-2005:02:51:00
10 rows selected.
This is the Requirement:
In a Form's Block(BLK1), for example: the current_record is the fifth record from the top
(i.e. 12-aug-2005:02:46:00)
When the fifth record is the current_record and When I click a button, three previous records of the
current_record should be populated on the screen.
See what I did:
I created another table same as the first table(ARCHIVE_DATA) and its name is: THREE_RECS.
I am inserting three records from the first table(ARCHIVE_DATA) into the second table: THREE_RECS
which are less than the current record and ORDER BY DESC.
CANVAS:
Two blocks (BLK1, BLK2) based on ARCHIVE_DATA and THREE_RECS are on the same CANVAS.
But the first block (BLK1) which is based on the first table:ARCHIVE_DATA is populated with one record and the
second block (BLK2) is empty.
So when I click a particular button (ex: prev_recs), the second block(BLK2) should be populated with
three previous records of the current record( :BLK1.COLL_TIME)
(off course :BLK2 populates with one record and use arrows or scrollbar to get the other two records)
This is the code I wrote in the trigger and followed by the error:
1 BEGIN
2 DECLARE
3 cursor c1 IS
4           SELECT MONITOR_ID,
5               SAMPLE_ID,
6               COLL_TIME,
7               DEW_POINT
8          FROM ARCHIVE_DATA;
9 cursor c2(passing_date IN date) IS
10           SELECT MONITOR_ID,
11               SAMPLE_ID,
12               COLL_TIME,
13               DEW_POINT
14          FROM (SELECT MONITOR_ID,
15               SAMPLE_ID,
16               COLL_TIME,
17               DEW_POINT
18          FROM ARCHIVE_DATA
19          ORDER BY COLL_TIME desc)
20      WHERE COLL_TIME < passing_date;
21     BEGIN
22     FOR cur_rec in c1
23     LOOP
24          IF (cur_rec.COLL_TIME = to_date(:BLK.COLL_TIME,'dd-mon-yyyy:HH24:mi:ss')) then
25     FOR second_cur_rec in c2(second_cur_rec.COLL_TIME)
26          LOOP
27      IF c2%rowcount < 4 then
28               BEGIN
29               INSERT INTO THREE_RECS
30                    values(second_cur_rec.MONITOR_ID,
31                         second_cur_rec.SAMPLE_ID,
32                         second_cur_rec.COLL_TIME,
33                         second_cur_rec.DEW_POINT);
34               COMMIT;
35               END IF;
36 END LOOP;
37 END IF;
38 END LOOP;
39 END;
40 END;
This is the error I am getting:
Error 103 at line 14
Encountered the symbol "(" when expecting one of the following
a PL/SQL variable or double quoted string
an expanded name
an expanded name link
a table reference __expression
a key word
Resuming parse at line 126, column 46
Thanks in advance

Answer 1

Change C2 to:
cursor c2(passing_date IN date) IS
  SELECT MONITOR_ID, SAMPLE_ID,
               COLL_TIME, DEW_POINT
    FROM ARCHIVE_DATA
    WHERE COLL_TIME < passing_date
    ORDER BY COLL_TIME desc;And rather than populating a table with the three records, you could just select the three records using: where COLL_TIME between Prev3_time and Prev1_time