Hello, i'm having this problem since a few months and its about a table i used in two differents forms and when you save a record in this table, sometimes it duplicates the record and when you try to made some operations with the table the application doesn't work, i have to shutdown the application.

I can do this with triggers or exists a better way in order to validate if the record exists previous saving it?.
Can you help me with some examples?

Thanks for the help.