In these we will use 19+1 exceptions.

it means  " When Others " is the last exception in

pl/sql block.execution will be end at When Others exception 

Stmt.

suresh.

suresh.somayajula@gmail.com

pre defined exception u should not have to declare in 
declare section 
ex. dul_value_error
    when_duplicate_row
etc

We can directly handle them in exception section need not 
to declare them. We need to declare them onle in case when 
we want to put user friendly message instead of oracle's 
default one.

Note: When others should be handle in last of exception 
handling part of block.

There are 20 pre-defined exceptions.

When an exception is raised,normal execution of your PL/SQL
block or subprograms stops and control transfers to its
exception-handling part.

User Defined exceptions are executed prior to system 
defined exceptions.

User defined exceptions  are executed in the order in which 
they are defined.