Informix Guide to SQL: Syntax SPL Statements

Use the RAISE EXCEPTION statement to simulate the generation of an error.

Use the RAISE EXCEPTION statement to simulate an error or to generate an error with a custom message. An ON EXCEPTION statement can trap the generated error.

If you omit the ISAM_error_var parameter, the database server sets the ISAM error code to zero (0) when the exception is raised. If you want to use the error_text_var parameter but not specify a value for ISAM_error_var, you can specify zero (0) as the value of ISAM_error_var.

The statement can raise either system-generated exceptions or user-generated exceptions.

For example, the following statement raises the error number -208 and inserts the text a missing file into the variable of the system-generated error message:

 RAISE EXCEPTION -208, 0, 'a missing file';

The special error number -746 allows you to produce a customized message. For example, the following statement raises the error number -746 and returns the quoted text:

 RAISE EXCEPTION -746, 0, 'You broke the rules';

In the following example, a negative value for alpha raises exception -746 and provides a specific message describing the problem. The code should contain an ON EXCEPTION statement that traps for an exception of -746.

	FOREACH SELECT c1 INTO alpha FROM sometable

	IF alpha < 0 THEN

	RAISE EXCEPTION -746, 0, `a < 0 found' -- emergency exit
	END IF

	END FOREACH

When the SPL routine executes and the IF condition is met, the database server returns the following error:

-746: a < 0 found.

For more information about the scope and compatibility of exceptions, see ON EXCEPTION.