I was just wondering what the syntax was for raising an exception in a trigger, I did a search in the developers manual and only saw this information:
Aborting statements and transactions
You might want a trigger action to be able to abort the triggering statement or even the entire transaction.
Triggers that use the current connection are not permitted to commit or roll back the connection, so how do you do that? The answer is: have the trigger throw an exception, which is by default a statement-level exception (which rolls back the statement). The application-side code that contains the statement that caused the trigger to fire can then roll back the entire connection if desired. Programming triggers in this respect is no different from programming any database-side JDBC method.
Could the above please be expanded on particularly the point where it mentions the programming of the exception.
Waqas aka Zafar