APEX 5.0 Cascading reports

Business case

You want to create a page with two or more reports that are connected with each other.  A kind of master-detail for reports.

In this example we show the list of departments and as a child report we show the employees of that department.

Solution

We start with building a blank page for our reports.  Add the different report regions on the page.  Whether you are using interactive reports or classic ones, it doesn't matter.  The solution works for both.

Once the reports are present and working independently, we can start making them connected.

The first report is called master and the second one is called the detail report.

Follow these steps to connect the reports:

1. Create the necessary page items to hold the information to be passed on to the detail report.  In my case this is only the primary key.  So I create a page item called P7_DEPT_PK_ID.  These page items can be set to hidden, since they have no added value for the end-user.  But for testing purposes, we lease them visible so we can see what is being passed on.  You can make them hidden, once everything is working correctly.
   
2. Now we need some javascript-code to pass the values of the current selected master record to these page items.  The easiest way is by using a link column on the master report.  As target for this link-column, we use an URL with the following destination:
   
   javascript:$s('P7_DEPT_PK_ID','#DEPARTMENT_ID#');
   You can see here that we are using a method called "$s", which can be used to put values in items.  As parameters we give the name of the destination parameter and the value, which in this case is the DEPARTMENT_ID from the currently selected master record.
   
   
   
   Some nice explanation on these javascript functions can be found in this blog: https://apex.oracle.com/pls/apex/germancommunities/apexcommunity/tipp/6341/index-en.html.
3. Once the value of the PK is now in this page item, we still need to refresh the detail report.  This can be done through the use of a dynamic action.  In this dynamic action we indicate that whenever the page item P7_DEPT_PK_ID is changed, we need to refresh the detail report.
   
4. The only remaining thing to do is to use the page item in the query of the detail report.
   
   
5. Because we are using javascript to fill in the page item, we need to submit the page item to the server, when we are refreshing the detail report.  This is done through the property 'Page Items to Submit' on the detail report.
   
   
6. Now you can run your solution

APEX 5.0 Example use of collections

This is my first attempt in using collections within Oracle APEX.
I just save this code for later use.

I used APEX 5.0 on the Oracle cloud.

I created 2 pages:

• Overview Page
• Edit Page

In the Overview page I load through a select-statement the data into a collection during the Pre-Rendering > Before Header > Processes > PL/SQL action, with the following code:

Declare
l_query varchar2(300) := 'select department_id, department_name, manager_id from departments';
l_coll_name varchar2(50) := 'DEPARTMENTS';
Begin
 APEX_DEBUG.ENABLE();
 APEX_DEBUG.INFO('Start fetchData');
    if not APEX_COLLECTION.COLLECTION_EXISTS(l_coll_name)
    then
    APEX_DEBUG.INFO('Collection ' ||l_coll_name||' does not exist, creating a new one');
      -- Create the collection from the query 
      APEX_COLLECTION.CREATE_COLLECTION_FROM_QUERY_B (
        p_collection_name => l_coll_name, 
        p_query => l_query);
    end if;
 APEX_DEBUG.INFO('End fetchData');
End;

I'm creating the collection only the first time that I'm entering the page.  So when changes are made on the second page, these changes are immediately shown on this page on returning.

To show the data in a report, you can use a classic report with a query which looks like this one:

select 
    c001,
    c002,
    c003,
    c004,
    c005
  from apex_collections
  where collection_name = 'DEPARTMENTS'
;

In this simple example, I just copy the values from the collections to the editable fields on the Edit Page through the link-functionality.
When showing the Edit page, I add a save button, which on submitting the page saves the changes in the collection and the db if needed.  These operations are performed in the Processing > Processes > PL/SQL code with the following code:

declare
  cursor c_get_seq
  is
  SELECT seq_id
   FROM APEX_collections
  WHERE collection_name = 'DEPARTMENTS'
    AND c001 = :P6_DEPTID
  ;
  r_seq c_get_seq%rowtype;
begin
   open c_get_seq;
   fetch c_get_seq into r_seq;
   if c_get_seq%found
   then
   APEX_DEBUG.INFO('Collection found, updating);
      APEX_COLLECTION.UPDATE_MEMBER (
        p_collection_name => 'DEPARTMENTS',
        p_seq => r_seq.seq_id,
        p_c001 => :P6_DEPTID,
        p_c002 => :P6_DEPTNAME,
        p_c003 => :P6_MANAGER);
        commit;
     -- update departments set department_name = :P6_DEPTNAME, manager_id = :P6_MANAGER where department_id = :P6_DEPTID;
   else
     APEX_DEBUG.ERROR('Collection not found!!');
   end if;
   close c_get_seq;
end;

After clicking on the save-button, the collection gets updated and the user returned to the previous page.