Should I check for DB constraints in code or should I catch exceptions thrown by DB

Question

I have an application that saves data into a table called Jobs. The Jobs table has a column called Name which has a UNIQUE constraint. The Name column is not PRIMARY KEY. I wond

Answer 1

The inner exception of the GenericADOException will tell you why the database action failed. You can catch the OracleException / MSSQLException / [InsertCustomExceptionHere] and handle the error from that message. If you want to pass this back up to the front end (assuming the user is the one who entered duplicate data) you might want to wrap it in a custom exception first so you don't couple your front end to your database. You don't really want to be passing RDBMS specific exceptions around.

I disagree with checking the db for uniqueness before doing an insert, round tripping to the database twice isn't very efficient and certainly isn't scalable if you have a high volume of user traffic.