I am currently doing a migration from MS Access database to Oracle database table. The migration process is automated by running an executable. The problem is that the records in the old database table contains duplicate entries. So how do I write a trigger that will compare the records in the new Oracle database table with the one that will be inserted that will fire before inserting. To my knowledge from my seniors, once a duplicate record is detected, the whole migration process will be stopped. What do i need to add into the trigger so that once a duplicate record is detected it will not insert it into the new table and resume to the next record to be migrated instead of stopping the whole process.