Reporting on assignment details with Discoverer

Question

I am tasked with reporting on an individuals 'Assignment Status' where their current assignment status is 'Secondment' and bring back previous details (e.g. organisation) before the change occurred. My problem is that I am getting multiple rows where other changes within assignment have occurred and all I want is the current details and the details at the row before the change to secondment.
This is an example of the data
Person Id     User Status     Effective Start Date     Effective End Date     Organization Name
1     Active Assignment     03/01/06     10/01/06     1924
1     Active Assignment     10/02/06     12/31/06     1941
1     Active Assignment     01/01/07     01/28/07     1908
1     Active Assignment     01/29/07     03/04/07     1908
1     Active Assignment     03/05/07     05/30/07     1908
1     Active Assignment     05/31/07     11/21/07     1908
1     Active Assignment     11/22/07     04/30/08     1908
1     Active Assignment     05/01/08     05/11/08     1908
1     Secondment     05/12/08     05/13/08     1941
1     Secondment     05/14/08     05/18/08     1941
1     Secondment     05/19/08     12/31/12     1941
I only want current information and latest row at active assignment.
We have attempted calculations using the LEAD/LAG and CASE WHEN functions (see below) to no avail.
Any help is greatly appreciated.
Thanks
CASE WHEN ( LAG(Assignment Start Date,20) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,20) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,19) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,19) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,18) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,18) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,17) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,17) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,16) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,16) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,15) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,15) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,14) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,14) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,13) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,13) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,12) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,12) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,11) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,11) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,10) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,10) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,9) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,9) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,8) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,8) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,7) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,7) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,6) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,6) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,5) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,5) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,4) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,4) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,3) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,3) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,2) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,2) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) WHEN ( LAG(Assignment Start Date,1) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ) IS NOT NULL THEN LAG(Assignment Start Date,1) OVER(PARTITION BY Employee Number ORDER BY Assignment Start Date DESC ) ELSE SYSDATE END
Edited by: user10440531 on 17-Oct-2008 08:42

Answer 1

Hi,
Perhaps something like that will give you what you need, pretty ugly but works...
You'll get the last 2 rows of assignments per user(person_id)
select *
from (--That selects the assignment information (all the asignment rows)
--The limit on the rows is in the outer select
SELECT count(a.effective_start_date) over (partition by a.person_id
order by a.effective_start_date desc) run_count
,a.effective_start_date
,a.effective_end_date
,a.person_id
,a.assignment_status_type_id
,HR_GENERAL.DECODE_POSITION_LATEST_NAME(A.POSITION_ID)
,HR_GENERAL.DECODE_ORGANIZATION(A.ORGANIZATION_ID)
FROM
PER_ALL_ASSIGNMENTS_F A
WHERE A.ASSIGNMENT_TYPE = 'E'
) assign
where assign.run_count <= 2 --gets the last 2 rows per person_id