Question

Define exception handling in your own words then justify, using at least four examples of pre‐ defined system exceptions. (10 marks)

Answer 1

exception handling is the process of responding to the occurrence of exceptional conditions requiring special processing during the execution of a program.

four examples of pre‐ defined system exceptions

DUP_VAL_ON_INDEX

Your program attempts to store duplicate values in a database column that is constrained by a unique index.

INVALID_CURSOR

Your program attempts an illegal cursor operation such as closing an unopened cursor.

LOGIN_DENIED

Your program attempts to log on to Oracle with an invalid username and/or password.

NOT_LOGGED_ON

Your program issues a database call without being connected to Oracle, while Oracle is waiting for a resource.