I am training a new Mendix developer in my company and today we encountered the difference between an Association Data source Type and Database Data source Type for a Datagrid. I find that I never use Association data source because of its limitations (unable to search, sort, access entities more than one step removed from base entity), and also because I can access the same functionality using a Database data source. It made me wonder if the association data source type is a relic from prior versions of Mendix, or if there is a use case I am missing. Does anyone have a use case for Association data source type vs. Database data source type? Perhaps someone from Mendix can comment about this....
Using a association datasource allows you to keep the objects in memory. This means that you can add new objects and see them in your form/grid without you actually commiting them. Kinda like with a reference set selector. This means that if you create a new oject A with several new objects B you can commit the objects B when you save/commit the A object. This will save you some cleaning of objects that excist in your database because users navigate away.