If you want to see a demo of building an app from multiple data sources then maybe you want to have a look at the Getting Started with QlikView webinar I presented a while back. This shows connecting to multiple data sources, joining the data together and then building an application from it. You should be able to access it at the following link
If you need to show the demo from your own data sources then your best bet is either to build it yourself, using the material above as a guide, or contact your local Qlik sales team to talk through your requirements and try to arrange a one on one session, though there might be a local charge for this depending on your region.
I need to accomplish the same (connect multiple data source like oracle, mysql & mongodb and map the record using case id and populate it as a result in separate sheet) in my project. Could you please provide access to your Webex recording