Exceptions : Exception « PL SQL Programming « Oracle PL/SQL Tutorial

1. Oracle PL/SQL Tutorial
2. PL SQL Programming
3. Exception

In PL/SQL, the user can catch certain runtime errors.

Exceptions can be internally defined by Oracle or the user.

Exceptions are used to handle errors that occur in your PL/SQL code.

A PL/SQL block contains an EXCEPTION block to handle exception.

There are three types of exceptions:

1. Predefined Oracle errors
2. Undefined Oracle errors
3. User-defined errors

The different parts of the exception.

1. Declare the exception.
2. Raise an exception.
3. Handle the exception.

An exception has four attributes:

1. Name provides a short description of the problem.
2. Type identifies the area of the error.
3. Exception Code gives a numeric representation of the exception.
4. Error message provides additional information about the exception.

The predefined divide-by-zero exception has the following values for the attributes:

1. Name = ZERO_DIVIDE
2. Type = ORA (from the Oracle engine)
3. Exception Code = C01476
4. Error message = divisor is equal to zero

The following is the typical syntax of an exception-handling PL/SQL block.

exception

  when exception_1 THEN

  statements

  when exception_2 THEN

  statements

  ...

exception_1 and exception_2 are the names of the predefined exceptions.

statements is the PL/SQL code that will be executed if the exception name is satisfied.