DatabaseConnection_SetConnectionStringForSession for a Mobile application

Is there a way for a MOBILE application to change the connection string for the External SQL Database connection at runtime?

I have multi-tenant WEB and MOBILE applications which interface with an external SQL database defined in ServiceCenter/Administration/Database Connections.  Each tenant has a different external SQL database with the same schema.

My WEB application calls DatabaseConnection_SetConnectionStringForSession from the PlatformRuntime_API to switch the connection after login. This is working well and my WEB app can successfully read/write data from their own external SQL database.

Now I am trying to extend the same functionality to my MOBILE application. But ... the value set from DatabaseConnection_SetConnectionStringForSession is being ignored, and all data is read from the same default tenant. 

This means that I haven't been able to deploy my multi-tenant mobile application to any other tenants?

Can anyone help me with this?



Here is the reply we got from João Barata in OutSystems support.
Note - the key seems to be using "Fetch data from other sources option" inside the mobile application. 
And even better - it appears to remember the connection string for subsequent requests. We didn't have to set the connection before every request, but just once after login. (caveat - we are still testing the solution, but looks good so far)

Thank you for reaching out to us.

The "DatabaseConnection_SetConnectionStringForSession" action does seems not to work in Mobile. However what is happening is that in Mobile eSpaces the session is not persisted between server requests, and therefore the change is not persisted.

Mobile eSpaces don't have session variables visible. But this does not mean the session variables have been completely removed from Mobile eSpaces in the platform, they still exist in references and extensions. This enables the possibility to have WebResponsive Espaces that have session variables and expose actions that are referenced from Mobile eSpaces. In these scenarios, the session variables exist can be assigned and read, but are not persisted between server requests.

Please let us present a possible solution. If you change the Connection in each request you should be able to get the proper outcome. Please feel free to explore more in the example below: 

The idea is that instead of using an aggregate to fetch the server database, you can use the "Fetch data from other sources option" and execute the database DatabaseConnection_SetConnectionStringForSession before calling the Aggregate or Advance Query to fetch the records. This needs to be done for each server request that you need to switch the database connection string.

We've created also a product defect to fix the documentation since it's not so clear in how to achieve this step.

Please let us know if this communication is clear and don't hesitate to ask any question that remains.

Best Regards,
João Barata | Customer Success