Input Reference Set Selector - implementation? Where the data is stored? How to access?
In documentation, there is some basic info: https://docs.mendix.com/refguide/input-reference-set-selector/. There is a nice example how we can choose in which Group a Customer belongs to. We set that a Customer belongs to Customer_Group/Group/Name. My question is, where is stored this information? For example information that the customer "John Doe" belongs to group "My group"? I understand that this is not stored in attributes of Customer or Group entities. I think there is a hidden link table (the association) between Customer and Group (there should be 2 columns with customer id and group id) and the information is stored in this way. Is it right? What if later I need to access this information somewhere, for example in microflow, how would I access it? Are we able to pull it from Customer_Group association? I would imagine if Customer is a parameter passed to my microflow, I could Retrieve a list of Groups that the Customer belongs to through Customer_Group. Do I understand all of this right?
In the background, Mendix always uses an extra table to store the associations. So for instance, if you have an association between Order and Customer, you'll always have a third table that stores the associations. You can see this if you open a database explorer (e.g. PgAdmin) as you'll be able to traverse the path between the tables via that third table.
Yes, you understand it. The Example with the Customer Parameter and then to Retrieve the List of Groups associated to the Customer is absolutely right.
A nice widget to set the reference and to let the User search for groups
Thank you Eline and Damir! Regarding the PgAdmin (I like Valentina btw), I understand you can use it if the underlying database is set to PostgreSQL but if we use just the built-in database which is HSQL I believe, we can not use it so we actually can not see link tables, right?