How to filter a form with pagination?

Question

Hi all,
I've converted an app to Apex 3.1 (thanks to helpful folks here), but am stuck on the final form. I'd like to streamline the master-detail form, skipping over the tabular report in the detail. Here's (almost) a shell of what I'm trying to do:
[http://apex.oracle.com/pls/otn/f?p=57085|http://apex.oracle.com/pls/otn/f?p=57085]
I'd like the select list in the top region to be able to filter the results in the lower region, showing one row of info at a time in a form. The above example isn't nearly as complex as the real form I'm using, of course, but it should show what I'm trying to do.
I've set up the computation for P1_EMPNO as:
select min(empno)
from "#OWNER#".emp
where deptno like :P1_DEPT_FILTER OR :P1_DEPT_FILTER IS NULL...with a conditional that P1_EMPNO is NULL. Likewise, the row fetch contains the same WHERE clause as above.
I've been running around in circles trying to debug this, prototyping several forms to test combinations of branches, SQL, and such, but no luck.
Has anyone done this before? I see some semi-close threads here, but they seem to end up as a report.
TIA!
Rich
Edited by: socpres on Dec 1, 2008 1:48 PM -- minor edit: changed SQL to use code tag

Answer 1

Hi Rich,
Sorry - just seen this.
Yes, I have done something similar before (though the filters were handled on a separate page, the principle would be the same).
The important parts are the selection of the first record, the IDs for the Next and Previous records, the conditional display of the Next/Previous buttons and how to set the current EMPNO id.
1 - As you have a form on the page already, the first record can be set using a Before Header page computation that is conditional on the PK field being null and using your code as the source:
select min(empno)
from "#OWNER#".emp
where deptno like :P1_DEPT_FILTER OR :P1_DEPT_FILTER IS NULL2 - You should then have hidden NEXT and PREVIOUS items on your page. These should be calculated using Before Header computations on EVERY page load (ie not conditional) and using SQL queries:
Previous (say Item name of P1_PREVIOUS_EMPNO):
select NVL(max(empno),0)
from "#OWNER#".EMP
WHERE DEPTNO LIKE :P1_DEPT_FILTER OR :P1_DEPT_FILTER IS NULL
AND EMPNO < :P1_EMPNONext (say Item name of P1_NEXT_EMPNO):
select NVL(min(empno),0)
from "#OWNER#".EMP
WHERE DEPTNO LIKE :P1_DEPT_FILTER OR :P1_DEPT_FILTER IS NULL
AND EMPNO > :P1_EMPNO3 - Your Next button should be conditional on P1_NEXT_EMPNO not being 0 and your Previous button should be conditional on P1_PREVIOUS_EMPNO not being 0
4 - The Next button should trigger a branch that sets the value of P1_EMPNO to P1_NEXT_EMPNO and your Previous button should set P1_EMPNO to P1_PREVIOUS_EMPNO
5 - Your branches triggered by the Filter and Reset buttons should reset P1_EMPNO to null (the computation will calculate this again)
Then, when the page loaded, the first EMPNO that matches the filter is determined and the next/previous EMPNO's are automatically calculated and the buttons shown/hidden as appropriate. Clicking Next or Previous will move through the records and new Next/Previous EMPNO's are calculated each time. When a new filter is applied or the page is reset, the EMPNO is cleared out and recalculated based on the current filter.
Andy