Extending a function with logic stored in a table?

Question

Let's say I have a function with local variables and I have a select statement in it. This statement populates (using into) these variables, one of which contains a condition which has the name of some local variables in it. I would like for this to be evaluated. Is this possible?
for example, if I have variables named local_value1, local_value2 and local_condition and local_condition is loaded from a table column in which the expression is: local_value1 < local_value2
I'd then need to do a: if local_condition then blah....
I've been looking at ways to use execute immediate to do this, but it doesn't look like I can do that, as it wont do substitution of local variables, only bound variables.
I've done this with various scripting languages in the past, but I've not seen anything on the forums on how to do this with pl/sql.
Any suggestions?

Answer 1

wether this is really meaningful or not ... here is a way:
michaels>  CREATE TABLE demo_logic
( demo_logic_id NUMBER,
demo_logic_statement VARCHAR2(4000),
CONSTRAINT demo_logic_pk PRIMARY KEY (demo_logic_id) ENABLE
Table created.
michaels>  -- The data:
michaels>  INSERT INTO demo_logic
     VALUES (1, 'local_value1 < local_value2')
1 row created.
michaels>  INSERT INTO demo_logic
     VALUES (2, '(local_value1 = local_value2) or (local_value1 < 7)')
1 row created.
michaels>  -- Then the function:
michaels>  CREATE OR REPLACE FUNCTION func_demo (condition_id IN NUMBER)
   RETURN NUMBER
IS
   local_value1            NUMBER                                 := 5;
   local_value2            NUMBER                                 := 2;
   local_value_to_return   NUMBER                                 := 0;
   local_condition         demo_logic.demo_logic_statement%TYPE;
BEGIN
   SELECT demo_logic_statement
     INTO local_condition
     FROM demo_logic
    WHERE demo_logic_id = condition_id;
--next we would evaluate 'local_condition' and if true we would then continue and do more work
--and assign something to local_value_to_return.
   EXECUTE IMMEDIATE 'DECLARE
                        local_value1 number := :1;
                        local_value2 number := :2;
                      BEGIN
                        IF '
                     || local_condition
                     || ' THEN
                          :out := 1;
                        ELSE
                          :out := 0;
                        END IF;
                      END;
               USING local_value1, local_value2, OUT local_value_to_return;
   RETURN local_value_to_return;
END func_demo;
Function created.
michaels>  SELECT func_demo ('1') res
  FROM DUAL
       RES
         0
1 row selected.
michaels>  SELECT func_demo ('2') res
  FROM DUAL
       RES
         1