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Exceptions

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: Predefined Oracle errors Undefined Oracle errors User-defined errors The different parts of the exception. Declare the exception. Raise an exception. Handle the exception. An exception has four attributes: Name provides a short description of the problem. Type identifies the area of the error. Exception Code gives a numeric representation of the exception. Error message provides additional information about the exception. The predefined divide-by-zero exception has the following values for the attributes: Name = ZERO_DIVIDE Type = ORA (from the Oracle engine) Exception Code = C01476 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.