Can I prevent duplicate values entry thru Forms Personalization

Question

We use Oracle Project. While entering key Members on Project Form, we want to prevent users to enter multiple "Project Accountant" within the same project. So essentially there should be only one "Project Accountant" per project. I have sql for this
SELECT 'X'
FROM PA_PROJECT_PLAYERS
WHERE PROJECT_ID = 11494
AND PROJECT_ROLE_TYPE = '1001'
AND ((START_DATE_ACTIVE BETWEEN START_DATE_ACTIVE AND NVL(END_DATE_ACTIVE, START_DATE_ACTIVE + 1))
OR (END_DATE_ACTIVE BETWEEN START_DATE_ACTIVE AND NVL(END_DATE_ACTIVE, END_DATE_ACTIVE + 1))
OR (START_DATE_ACTIVE BETWEEN START_DATE_ACTIVE AND NVL(END_DATE_ACTIVE, START_DATE_ACTIVE + 1)))
AND (PROJECT_PARTY_ID IS NULL OR PROJECT_PARTY_ID != PROJECT_PARTY_ID) ;
But I am not able to figure out how to put this into Forms Personlization. Can someone help.
Thanks
Rakesh

Answer 1

Deekshitulu,
The seat assignment column in your table - is it part of the Primary Key on the table? If so, you can set the "Enforce Primary Key" property on your data block. More than likely, the seat assignment column is not part of your PK, so you will need to perform a check in your When-Validate-Item trigger on the Seat_Assignment column to check if the seat has already been assign to someone else. This is pretty basic stuff, so I'm guessing you are new to Oracle Forms or this is Classwork. Based on your example, I'd say it is class work, therefore, I'm not going to give you a detailed code sample. I'll just give you the basics and let you provide the details. Here goes...
-- When-Validate-Item
-- Check for duplicate seat assignment
DECLARE
   nDummy   NUMBER;
BEGIN
   BEGIN
      SELECT -- some type of count to see if the seat has been assigned already
        INTO nDummy
        FROM chair_assignments
       WHERE seat_number = :my_data_block.seat_number;
   EXCEPTION when no_data_found THEN
       -- Seat is not assigned.  What to do now?
       nDummy := 0;
   END;
   -- Check my Dummy Variable to see if the seat has an assignment record.
   IF nDummy > 0 THEN
      -- UhOh, my seat is already assigned.
      --RAISE and error to stop the form and prevent the double assignment
   END IF;
END;If this is not classwork, I apologize for the assumption and would be happy to elaborate on my answer. If this is classwork, please let me know and if you need me to elaborate on my answer - I'd be happy to. We don't mind helping people learn Oracle we just don't want to do your homework/class assignments for you. :-)
Hope this helps.
Craig...