Hi @Anonymous
There is a simple approach, let's try that first and see if it works and what performance is like. Then I suggest you try caching, see the performance improvement, and then choose which approach you prefer.
Simple approach:
Filter('[dbo].[CONTACT]', ID in Filter('[dbo].[CUSTOMER_CONTACT]', CustomerID = DropDownListCustomer.Selected.CustomerID).ContactID)Basically the in operator works by selecting all contacts where the ID is included in the list of ContactID returned by your original filter.
This approach may not work due to both delegation (if your tables have >500 rows) and performance issues.
Caching approach:
Create a welcome screen with a button to navigate to the rest of the app. The button, before navigation, should cache the contact and customer_contact tables as local collections. Then you can substitute these in the formula above. You should be able to find techniques for caching >500 rows in other posts including mine.
Please let me know how you get on.
