Stored functions defined with output parameters

Starting with IDS 10.00, IBM^® Informix^® introduced the concept of output parameters for stored functions.

To retrieve the output parameters, you must execute the routine in a SELECT statement defining Statement Local Variables. These variables will be listed in the select clause to be fetched as regular column values. See Informix documentation for more details.

In order to retrieve returning values into program variables, use an INTO clause in the EXECUTE instruction.

This example shows how to call a stored function with output parameters:

MAIN
    DEFINE pi, pr INTEGER
    DATABASE test1
    EXECUTE IMMEDIATE "create function proc2(i INT, OUT r INT)"
                    ||" returning int;"
                    ||" let r=i+10;"
                    ||" return 1;"
                    ||" end function"
    PREPARE s FROM "select r from systables where tabid=1 and proc2(?,r#int)==1"
    LET pi = 33
    EXECUTE s USING pi INTO pr 
    DISPLAY "Output value: ", pr 
    EXECUTE IMMEDIATE "drop function proc2"
END MAIN