Generating optional FK items in Designer R.1.3

Question

I have a form which is based on some tables as follows:
Table1: PK = COL1.
Table2: PK = COL1 + COL2 (i.e. has an FK to Table1).
Table3: Has a mandatory FK to Table1 i.e. COL1 must be entered. Table3 also has an optional FK to Table2 i.e. COL2 is optional.
Don't ask me why - this is the data model I have to work with.
The tables etc can be generated fine with this kind of structure.
My form is based on Table3 i.e. it should have a mandatory item COL1 plus an optional item COL2.
The problem is in trying to generate this form from Designer R1.3. If I define the FK to Table2 as optional, Designer refuses to generate the form because the optional FK includes mandatory columns (COL1). If I define the FK as mandatory, Designer insists that all the FK columns are mandatory i.e. COL2 is made mandatory instead of optional in the generated form.
I've tried looking at the preferences e.g. setting the preference NIVVKC to Y for the table/constraints and for the form.
But nothing seems to work. In Developer 2000 this can be done in 5 minutes; in Designer it seems to be virtually impossible. Does anyone out there know how to get this kind of thing to work, and how to explain it to me in nice easy-to-understand words?
Chris

Answer 1

Chris,
If you have a table 3 like yours, Designer expects the foreign keys to be set up as follows:
* col1a: mandatory FK to table 1 - col 1
* col1b + col2: both optional, FK to table 2 - col1 + col2
As you noticed, the forms generator does not allow you to reuse col1 in both foreign keys, as one is optional and one is mandatory. The only solution that I know of is to add another optional column, which is only filled if the FK to table 2 is present, and in that case it is exactly the same as the col1 column that you already had.
Hope this helps,
Sandra