Oracle Apex Validation - Valid Product Name - oracle

Question

I have a Validation beginner's question here:
I have a select list item, options:
Product
SKU
If the user selects the SKU option a new textfield Item is shown for the customer to write down the SKU number.
My validation then tries to prevent an invalid SKU to be inserted.
This is what I have so far:
declare
v_rows_approved_min number;
v_rows_approved_max number;
err varchar2(300);
begin
if :P8_PRODUCT_OR_SKU = 'SKU' -- THIS IS MY SELECT LIST ITEM
then
err := 'Not a valid SKU';
v_rows_approved_min := 1;
select count(*) into v_rows_approved_max from SKU_TABLE;
for cur_a in (select SKU from SKU_TABLE)
loop
exit when v_rows_approved_min > v_rows_approved_max;
if :P8_SKU = cur_a.SKU
then return err;
else null;
end if;
v_rows_approved_min := v_rows_approved_min + 1;
end loop;
else null;
end if;
end;
Not sure what's going on here, can anyone help please?
Thanks!

Answer 1

This code is overly complex. It checks if a page item value exists in a table and returns an error if a match is found. This is done with a loop with some additional logic to exit the loop with the number of iterations reaches the select count. That last logic is not needed. If a table contains 5 rows, then the loop will have 5 iterations. No need to do a SELECT count from the table (v_rows_approved_max) and then check every iteration if that number has not been reached yet...
Also, there is no RETURN statement if not match is found, so that is added at the end.
Here is an attempt at a rewrite:
DECLARE
---- not needed
-- v_rows_approved_min NUMBER;
-- v_rows_approved_max NUMBER;
err VARCHAR2(300) := 'Not a valid SKU';
BEGIN
IF :P8_PRODUCT_OR_SKU = 'SKU' -- THIS IS MY SELECT LIST ITEM
THEN
---- err can be defaulted in declaration
--err := 'Not a valid SKU';
--v_rows_approved_min := 1;
---- not needed see below
--SELECT COUNT(*) INTO v_rows_approved_max FROM sku_table;
FOR cur_a IN ( SELECT sku FROM sku_table ) LOOP
---- not needed. You're looping through the table, v_rows_approved_min will be > than v_rows_approved_max
--EXIT WHEN v_rows_approved_min > v_rows_approved_max;
IF :P8_SKU = cur_a.sku THEN
RETURN err;
---- not needed
-- ELSE
-- NULL;
END IF;
---- not needed
-- v_rows_approved_min := v_rows_approved_min + 1;
END LOOP;
---- not needed
-- ELSE
-- NULL;
END IF;
-- you need to return something whenever the function ends...
RETURN NULL;
END;
/
however...
This can be greatly simplified.
Create a validation of type "Rows returned"
Source:
SELECT
1
FROM
sku_table WHERE sku = :P8_SKU
Error Message: Not a valid SKU
Server Side condition (Type Item = Value): Item: P8_PRODUCT_OR_SKU; Value: SKU
This does exactly the same thing.