PL/SQL questions

[Quoted] I have two tables

[Quoted] Enroll (StudentID, courseId, paymentoption) Bills (bill_no, studentid, courseid, coursefees, interest, total)

the primary key of enroll (studentid + courseId) is the foreign key of bills.
the primary key of bills is bill_no which is a sequence

now the problem.

I have write a program which will do the following

When one inserts an enroll record, the program should insert a bill for that student itself. and it should be complicated enough to tackle the payment option thing, as in if the paymentoption is cash then give two percent discount based on that calculate totals. otherwise not.

Notice that the coursefees attribute of bills should be derived from the table courses(courseid, coursefees)

In plsql i tried to write a trigger for enroll dept which satisfies certain conditions. The problem is that if a tuple passes the constraints in the trigger then... i get an error that says that violates the foreign key constrain of bills table. and to think of it it makes sense, because I called the procedure insert bill from the trigger itself....so even before the enroll record is inserted in enroll table it tries to insert that record in bills table and that gives me a foreign key violation. does anyone know how to come around this problem???

Thanks in advance
piyush

may be i m trying to do too much.... Received on Mon Apr 29 2002 - 19:09:58 CEST