EXCEPTION Clause


Exception Clause

|--EXCEPTION--+-exception_num-+--------------------------------->
              '-exception_var-'   

   .-,--------------------------------------.   
   V                                        |   
>----information-- = -+-CLASS_ORIGIN------+-+-------------------|
                      +-CONNECTION_NAME---+     
                      +-INFORMIX_SQLCODE--+     
                      +-MESSAGE_LENGTH----+     
                      +-MESSAGE_TEXT------+     
                      +-RETURNED_SQLSTATE-+     
                      +-SERVER_NAME-------+     
                      '-SUBCLASS_ORIGIN---'

Element	Description	Restrictions	Syntax
exception_num	Number of exceptions	Integer in range `1` to `35,000`	Literal Number
exception_var	Variable storing exception_num	Must be SMALLINT or INT	Language specific
information	Host variable to receive the value of a specified exception field	Data type must match that of the specified field	Language specific

The exception_num literal indicates one of the exception values from the number of exceptions that the NUMBER field in the Statement clause returns.

When retrieving exception information, GET DIAGNOSTICS writes the values of each of the seven fields into corresponding host variables. These fields are located in the diagnostics area and are derived from an exception raised by the most recent SQL statement.

The host-variable data type must be the same as that of the requested field. The following table describes the seven exception information fields.

Field Name Keyword	Field Data Type	Field Contents	ESQL/C Host Variable Data Type
RETURNED_SQLSTATE	Character	SQLSTATE value	char[6]
INFORMIX_SQLCODE	Integer	Informix®-specific status code	int4
CLASS_ORIGIN	Character	String	char[255]
SUBCLASS_ORIGIN	Character	String	char[255]
MESSAGE_TEXT	Character	String	char[255]
MESSAGE_LENGTH	Integer	Numeric value	int
SERVER_NAME	Character	String	char[255]
CONNECTION_NAME	Character	String	char[255]

The application specifies the exception by number, using either an unsigned integer or an integer host variable (an exact numeric with a scale of 0). An exception with a value of 1 corresponds to the SQLSTATE value set by the most recent SQL statement other than GET DIAGNOSTICS. The association between other exception numbers and other exceptions raised by that SQL statement is undefined. Thus, no set order exists in which the diagnostic area can be filled with exception values. You always get at least one exception, even if the SQLSTATE value indicates success.

If an error occurs within the GET DIAGNOSTICS statement (that is, if an invalid exception number is requested), the Informix internal SQLCODE and SQLSTATE variables are set to the value of that exception. In addition, the GET DIAGNOSTICS fields are undefined.