I have a 3rd party application that maintains a customer master file (update, insert, delete) and I cannot alter their programs. I would like to put a trigger on the database file to fire an external program on insert and determine if the insert should be performed. If not, I would like to send a message to the user and abort the insert.
I have written a trigger program to determine if the update should happen and send a message to the user but I do not know how to force the calling program to abort without performing the insert.
Does anyone know if this is possible and if so, how?