handling duplicates in a form

[Phjr]

hi, in a before_update delegate i find that i am about to add a duplicate field, how can i revert/rollback ?

How about errors while working with an (ODBC) virtual table, is "on error" the way to go?
Regards

I may have the beginning of a solution for duplicates using syncnum() in before_update delegate.
When detecting a duplicate (duplicate record appears in table even before validating) i do a delete where syncnum() = syncnum of duplicate record (obtained by syncnum() in before_update delegate).
Works well on local and virtual tables.
Regards