I'm using Dynamic Data with Entity Framework in VS2010.
Let's say my table has these fields:
Hypothetical scenario (it's easier for me to explain this way, so just bear with me for now)... But let's say each row in the table represents "how many items were sold by such-and-such employee at such-and-such location," where location and person are foreign keys which are referencing other tables. Basically, there should be no more than a ONE row which has a particular combination of Person and Location. Makes sense?
So, when inserting new rows using my Dynamic Data app, the insert form displays editable fields for Person (dropdown), Location (dropdown), and Items Sold (textbox). How do I prevent users from inserting another row into the table containing an already-existing combination of Person and Location? How do I displaying useful feedback to them in the event that they DO attempt to do this?
I have several thoughts about this, but since I'm new to Dynamic Data, I'm not sure which way to go. For example:
Option 1: Use "cascading dropdowns" approach in the insert form and only pull in the "allowed" combinations of the two dropd
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