When you include ports as arguments in a private user-defined function, you must also include the ports as arguments in any public function that contains the private function. Use the same datatype and precision for the arguments in the private and public function.
For example, you define a function to modify order IDs to include ‘INFA’ and the customer ID. You first create the following private function called ConcatCust that concatenates ‘INFA’ with the port CUST_ID:
CONCAT (‘INFA’, CUST_ID)
After you create the private function, you create a public function called ConcatOrder that contains ConcatCust:
CONCAT (:UDF.CONCATCUST( CUST_ID), ORDER_ID)
When you add ConcatCust to ConcatOrder, you add the argument CUST_ID with the same datatype and precision to the public function.
If you enter a user-defined function when you manually define the public function syntax, you must prefix the user-defined function with :UDF.