Database errors are exposed as exceptions thrown. You don't have a centralized DBError event. Instead in code that builds up a transaction and COMMIT you will need to surround that code with TRY-CATCH.

Part of that exception handling should be perform ROLLBACK.

Exceptions with .NET DataStore:

1. Open SnapDevelop
2. On Start Page >
   Section DataWindow Converter & .NET DataStore >
   Select CRUD Operations with .NET DataStore
3. On the new web page >
   Within content list on right side >
   Select Perform CRUD Operations Using the Web API
4. Several code examples on this page
   1. Catch exception for Retrieve
   2. Catch Exception for Update
   3. etc.

HTH /Michael