Revolutionize Your APEX Apps with Background Processes and Collections – See How It’s Done!

Handling Oracle APEX Collections with Background Processes: A Quick Tip

It's important to understand that Oracle APEX collections are typically tied to a specific user session. Recently, I encountered an issue when I tried populating a collection through a background process. Once the process finished, I checked the collection, but no data was found. Oddly enough, the same logic worked perfectly when tested in SQL Developer.

The Quick Fix:

The key here is that background processes run with a different session ID. As a result, the collection is populated within the background process's session—not the user’s session. To address this, you need to ensure that you handle the session context properly.

First adjust your PL/SQL Procedure:

PROCEDURE fill_collection(
        p_app_id in number
      , p_page_id          IN NUMBER
      , p_session_id       IN NUMBER) AS
        v_sql      CLOB;
       BEGIN

    -- Attach to APEX session !!
        apex_session.attach(  p_app_id => p_app_id 
                            , p_page_id => p_page_id
                            , p_session_id => p_session_id);

      v_sql := 'select * from dual';

        apex_collection.create_collection_from_queryb2(
                        p_collection_name => 'MY_SESSION_MY_COLLECTION'
                      , p_query => v_sql
                      , p_truncate_if_exists => 'YES') ;

     apex_session.detach;

     EXCEPTION
        WHEN OTHERS THEN
            apex_session.detach;
            RAISE;
END;

2nd Save your Session ID:
On Page itself (eventually Page 0) you need following on Page Load:

on Process we cannot use directly APEX_CUSTOM_AUTH.GET_SESSION_ID so we need this Item.

3rd)
Use in the Background Prozess (INVOKE API in my case) with parameter p_session_id etc.

Result)
After the Process was finished now our Interactive Grid was filled with data:

Example SQL:
IG Region with this Query gives me now a result..

select * 
from apex_collections_dml 
where collection_name = 'MY_SESSION_MY_COLLECTION';

Happy Trying!