PL/SQL recursive calls: recursion in Oracle

PL/SQL does support recursion via function calls. Recursion is the act of a function calling itself, and a recursive call requires PL/SQL to create local copies of its memory structures for each call.

PL/SQL allows sub procedures or functions to be called recursively. The tutorial example below shows you how to calculate factorial values with a recursive sub function.

CREATE OR REPLACE

PROCEDURE FACTORIAL_TEST( N NUMBER )

AS

FUNCTION FACTORIAL( N NUMBER )

  RETURN NUMBER

AS

BEGIN

  IF N <= 1 THEN

    RETURN 1;

  ELSE

    RETURN N*FACTORIAL(N-1);

  END IF;

END;

BEGIN

  DBMS_OUTPUT.PUT_LINE('Factorial of '||N||' = ' || TO_CHAR(FACTORIAL(N)));

END; 

DECLARE

  N NUMBER;

BEGIN

  N := 10;

  FACTORIAL_TEST(

    N => N

  );

END;

Factorial of 10 = 3628800