Any aussies in this forum?

[1jet]

Hi all,
Just wondering whether any aussies can help me here. I don't mind help from others, but my question involves the Australian Tax File Number (TFN) and Australian Business Number (ABN).

Basically the rules with the Australian employment and tax system is that (when you're legal to work of course) everyone has ONE TFN each (ie One-to-Many but not mandatory).

If later you want to start a business, you must register an ABN under your TFN (meaning its not mandatory). If for example you want to start another business totally different from your first (eg comp shop first....then a cafe) you'll have to add another ABN (now meaning that the relationship between a TFN and ABN is One-to-Many but not mandatory).

Here's how the relationships are in my DB so far.

By f22a at 2008-10-27

My question is, how do I create just a One-to-One relationship between tblEmployee-TFN and tblEmployeeBusiness-TFN? Or is that what the intermediate relationship type means?

 

[TIbbs]

I am not in Australia but if the TFN is unique to an employee, then it is the attribute of the tblemployee, which you have correctly on your table.
But the relationship between tblemployee and tblEmployeeBusiness should be of 1 to many optional same as for tblBusiness.
Your tblEmployeeBusiness will then hold all records of each TFN assigned to a ABN.
So you are in the right tracks your intermediate relationship holds all this details for you.
usually in my opinion if you have a one to one relationship, chances are you normalization is wrong or the fields are actually attributes of just one of the tables.

 

[1jet]

Thanks. I don't know why I couldn't figure it out at first.

I eventually came to the same conclusion as you.
I've changed the tblEmployee - tblEmployeeBusiness relationship to one-to-many by having tblEmployeeBusiness with just Employee ID and ABN as the fields.
tblEmployee's TFN field does not need to be a key at all, the Employee ID should do.