Allow users to create reports based on their own selection of fields

Question

Is there a way to allow users to create reports based on their own selection of fields?
And if there is a way, then how?
In access we retrieve all demographic info on one screen and on another screen user can be able to choose specific fields from a list box to import data into file.

Answer 1

Hi,
This can be handled in various ways - but the principles are the same.
You need to apply conditional displays to all of the columns that your user can select and base the display of a column on the value of a field on the page.
You can have a series of Yes/No options - one for each field and base the display on the corresponding field being Yes. Or you can use checkboxes.
However, if you wish to use a multiselect list (which is probably easier as you can dynamically generate the list of field names), you will need to have hidden fields that will store either Y/N or 1/0 (I use ones/zeros) and have the conditional displays watch these fields instead. Populating these hidden fields is a bit more tricky than just having fields on the page that the user can control, but is doable:
1 - Create one hidden field for each field in the report that you want to show/hide. Put these fields in the same region as the select list in a region above the report
2 - Set conditional display values to "Value of Item in Expression 1 = Expression 2" and use the appropriate hidden field for Expression 1 and in Expression 2 enter in 1
3 - Create a page process that runs on submit, and create PL/SQL code something like:
DECLARE
lFields HTMLDB_APPLICATION_GLOBAL.VC_ARR2;
vField VARCHAR2(1000);
BEGIN
:P31_SHOW_EMPNO := 0;
:P31_SHOW_ENAME := 0;
:P31_SHOW_JOB := 0;
:P31_SHOW_MGR := 0;
:P31_SHOW_HIREDATE := 0;
:P31_SHOW_SAL := 0;
:P31_SHOW_COMM := 0;
:P31_SHOW_DEPTNO := 0;
lFields := HTMLDB_UTIL.STRING_TO_TABLE(:P31_FIELDS);
FOR i IN lFields.FIRST..lFields.LAST LOOP
vField := lFields(i);
IF vField = 'EMPNO' THEN
:P31_SHOW_EMPNO := 1;
ELSIF vField = 'ENAME' THEN
:P31_SHOW_ENAME := 1;
ELSIF vField = 'JOB' THEN
:P31_SHOW_JOB := 1;
ELSIF vField = 'MGR' THEN
:P31_SHOW_MGR := 1;
ELSIF vField = 'HIREDATE' THEN
:P31_SHOW_HIREDATE := 1;
ELSIF vField = 'SAL' THEN
:P31_SHOW_SAL := 1;
ELSIF vField = 'COMM' THEN
:P31_SHOW_COMM := 1;
ELSIF vField = 'DEPTNO' THEN
:P31_SHOW_DEPTNO := 1;
END IF;
END LOOP;
END;
4 - Finally, add a button that generates the report - this just needs to submit the page and branch back to the same page
I've used the standard EMP table for this example and my hidden fields are P31_SHOW_fieldname. The code resets the hidden fields to 0, checks if the user has selected the field from the list (P31_FIELDS) and changes the hidden fields value to 1 for all those selected. When the page is re-rendered, the report hides the columns where the hidden field value is 0 and displays those where it is 1. The export option will then only export those fields that are displayed.
You can see an example of this here:
http://htmldb.oracle.com/pls/otn/f?p=33642:31
Regards
Andy