How can I save the first dept. for an employee in a transport table?

Question

Hi All,
I have created a table to store the transports to an employee from department to another department.
the first department number to every employee is stored at the parent table called employees.
when I insert a new record to the transports table (which is the child for the parent employees) for an employee and the manager agrees for this transport the original value of department number in employees table will be changed to the new one. I done this process through a db trigger on the transport table.
Now the problem is that the original value of the first department number will be lost cause of the db trigger that changes this value after manager agreement!
I looked to solve the problem by adding a new column in employees table to save the first dept. no. for each employee only if Count of records = 1 for that employee like this:
-- Before Update DB Trigger on Transports Table:
DECLARE
pragma autonomous_transaction;
N NUMBER;
BEGIN
SELECT count(EMP_SID) -- emp-sid is the FK referenced from employeess.emp_sid
INTO N
FROM TRANSPORT_TRANS
where emp_sid=:NEW.EMP_SID
GROUP BY EMP_SID;
     IF :NEW.AGREE_FLG = 1 AND N = 1 THEN -- If the manager agrees and this record is the first one for that employee
     UPDATE EMPLOYEESS E
     SET E.FST_AD=E.ADMINISTRATION_SID, -- E.ADMINISTRATION_SID has the oroginal value for admin no. and FST_AD is the new column to save the first value
            E.FST_HE=E.HEADQUARTERS_SID,
            E.ADMINISTRATION_SID = :OLD.ADMIN_SID, -- changing the value with then new one added on the table
            E.HEADQUARTERS_SID = :OLD.HEAD_SID
           WHERE E.EMP_SID = :OLD.EMP_SID;
     ELSIF :NEW.AGREE_FLG = 1 AND N != 1 THEN -- if the manager agrees but the record is not the first record for that employee
     UPDATE EMPLOYEESS E
        SET   E.ADMINISTRATION_SID = :OLD.ADMIN_SID, -- only change the original  values
                 E.HEADQUARTERS_SID = :OLD.HEAD_SID
                 WHERE E.EMP_SID = :OLD.EMP_SID;
     END IF;
END;But the form gives me this error if I deleted (pragma autonomous_transaction;) st. :
ORA-04091: table transports is mutating, trigger/function may not see it
But when I keep it, the form gives me this error:
ORA-06519: active autonomous transaction detected and rolled back
Edited by: Dev. Musbah on Aug 18, 2009 2:09 AM

Answer 1

Dev. Musbah,
First make sure that the insert statement executes. And check whether other error messages are getting. Currently you are checking only NO_DATA_FOUND. so change the exception part with
EXCEPTION
     WHEN NO_DATA_FOUND THEN NULL;
     WHEN OTHERS THEN MESSAGE('Some Error Occured');Regards,
Manu.
If this answer is helpful or correct, please mark it. Thanks.