How to show multipe records on a single record

Question

Hi all,
I have a query which can contain 1 or Many records for each S.WAS_NO or APPL_NO even. A new record is created when the APPL_STATUS changes and a timestamp is created in APPL_STATUS_CHANGE_DATE.
select distinct
       S.APPL_ID,
       S.WAS_NO,
       S.AS_STATUS,
       S.STATUS_CHANGE_DATE,
       dense_rank() over (partition by S.WAS_NO order by S.STATUS_CHANGE_DATE) rank
  from table_a S, table b S2
where S.APPL_ID = S2.APPL_ID
order by S.WAS_NO, rank asc;
Current Results:
APPL_ID---WAS_NO---------------AS_STATUS----STATUS_CHANGE_DATE-----RANK
6628-------E4G0YL9B08V0V6---ASSIGNED-------25/10/2011----------------------1
6628-------E4G0YL9B08V0V6---USED--------------30/12/2011----------------------2
Desired Results:
APPL_ID--WAS_NO------------------AS_STATUS1----STATUS_CHANGE_DATE1----AS_STATUS2----STATUS_CHANGE_DATE2
6628-------E4G0YL9B08V0V6----ASSIGNED---------25/10/2011------------------------USED--------------30/12/2011The rank is based on the WAS_Number and ordered by the STATUS_CHANGE_DATE so i know which order they should go in.
I want to show 1 record per WAS_NO and show each status change with its date. There can only be a maximum of three status changes.
I have not been able to workout how to get Multiple records onto a singe record and in different columns.
Many thanks

Answer 1

This should do what you want:
WITH t AS
(SELECT 6628 appl_id, 'E4G0YL9B08V0V6' was_no, 'ASSIGNED' as_status, TO_DATE('25/10/2011', 'DD/MM/YYYY') status_change_date FROM dual UNION ALL
SELECT 6628 appl_id, 'E4G0YL9B08V0V6' was_no, 'USED' as_status, TO_DATE('30/12/2011', 'DD/MM/YYYY') status_change_date FROM dual UNION ALL
SELECT 6628 appl_id, 'E4G0YL9B08V0V6' was_no, 'COMPLETE' as_status, TO_DATE('15/01/2012', 'DD/MM/YYYY') status_change_date FROM dual UNION ALL
SELECT 6629 appl_id, 'A5AAFG1C07L0P2' was_no, 'ASSIGNED' as_status, TO_DATE('19/01/2012', 'DD/MM/YYYY') status_change_date FROM dual)
SELECT   appl_id,
         was_no,
         MAX(CASE rank
         WHEN 1 THEN as_status
         ELSE NULL
         END) as_status1,
         MAX(CASE rank
         WHEN 1 THEN status_change_date
         ELSE NULL
         END) status_change_date1,
         MAX(CASE rank
         WHEN 2 THEN as_status
         ELSE NULL
         END) as_status2,
         MAX(CASE rank
         WHEN 2 THEN status_change_date
         ELSE NULL
         END) status_change_date2,
         MAX(CASE rank
         WHEN 3 THEN as_status
         ELSE NULL
         END) as_status3,
         MAX(CASE rank
         WHEN 3 THEN status_change_date
         ELSE NULL
         END) status_change_date3
FROM    (SELECT appl_id,
                was_no,
                as_status,
                status_change_date,
                DENSE_RANK() OVER (PARTITION BY was_no ORDER BY status_change_date) rank
         FROM   t)
GROUP BY appl_id,
         was_no