foreign Key creation SQL help needed!

This is for an SQL class homework assignment. ..Now that that's out of the way :)

problem 1 was
to create a table with a
colA of type Number
and
colB which was varchar2(20)

problem2 was -
To make colA and colB a composite primary key

Now I have to (problem3)...

--Change the homework table so that colB can only contain values that
--are stored in the order# column of the orders table. Make certain
--that after the change, colB is still part of the composite key
--primary key created in step two.

I did the first two problems, but when I try to create the foreign key (which I believe is what I need to do to acheive the above) I got an error that the column type is incompatable with the referenced column type. ((The order# column in orders is Number))

I ended up doing...

ALTER TABLE SCOTT.HOMEWORK
        MODIFY COLB NUMBER;  ALTER TABLE SCOTT.HOMEWORK
 ADD CONSTRAINT COLB_ORDERS_ORDER#_FK
 FOREIGN KEY (COLB)
 REFERENCES SCOTT.ORDERS (ORDER#)
 ON DELETE CASCADE;

But I wonder if I was somehow supposed to make it work with the colB still being varchar2 type..

Anyone have any thoughts on that? or advice?

Thanks afforhand :)

Tony! Received on Thu Oct 23 2003 - 22:39:45 CDT