Convert a Recursive Query to parameterized query

Question

What is the best approach to parameterize a recursive query?

As an example, let's take the following query: (taken from postgresqltutorial):

WITH RECURSIVE subordinates AS (
 SELECT
 employee_id,
 manager_id,
 full_name
 FROM
 employees
 WHERE
 employee_id = 2
 UNION
 SELECT
 e.employee_id,
 e.manager_id,
 e.full_name
 FROM
 employees e
 INNER JOIN subordinates s ON s.employee_id = e.manager_id
) 
SELECT *
FROM subordinates;

How could I modify it to allowed me to pass employee_id as a parameter or clause of my query?

I found a solution where I put this query in a function that receives employee_id as parameter and return a table (with employee_id, manager_id, full_name columns), but I'm not sure if this is a good/elegant solution.

CREATE OR REPLACE FUNCTION func_subordinates(employee_id_param INT)
RETURNS TABLE (
 employee_id INT,
 full_name VARCHAR,
 manager_id INT) AS
$BODY$
BEGIN
 RETURN QUERY
 WITH RECURSIVE subordinates AS (
 SELECT
 employee_id,
 manager_id,
 full_name
 FROM
 employees
 WHERE
 employee_id = employee_id_param
 UNION
 SELECT
 e.employee_id,
 e.manager_id,
 e.full_name
 FROM
 employees e
 INNER JOIN subordinates s ON s.employee_id = e.manager_id
) 
SELECT *
FROM subordinates;
IF NOT FOUND THEN
 RAISE EXCEPTION 'No found %.', 1ドル;
END IF;
RETURN;
END;
$BODY$
LANGUAGE plpgsql;

Could I get the same result using a VIEW where employee_id could be passed as a clause or something like that?

Any suggestion will really appreciated.

• Frank Heikens: Offtopic: Are you sure about the EXCEPTION? Not finding any result is imho not an exception, it's normal behaviour for a database when there is no data that matches your request.
• VeryNiceArgumentException: @FrankHeikens, it really depends the case. It is just a bit of business logic inside this function. But I agree with you that in the majority of the cases it should not be an exception.
• user330315: Views can't have parameters. Using a function is the only option you have here as far as I can tell.
• wildplasser: BTW: the function could be made LANGUAGE sql;
• jjanes: You do it the same way you would if it were not recursive.