Design Issues - URGENT!!!

[samosa]

I inherited a table that was poorly designed.
No primary key and several duplications.
For instance, each table has id has several values.
I broke the tables into 3 - master table with unique entries, the other 2 tables with duplicate entries.
Now, I know I have to design it with 1:m relationship but the problem I am having is that while the master table has unique values for instance idnum has unique values but idnum has some null values in the other 2 two tables.
Can anyone tell me how I can link these two tables with the master table?
I hope this is not confusing.
thanks in advance!

 

[ggreg]

When I have had the same problem...what i
have done is run a query on the nulls and
come up with a numbering system for the nulls
like N1..N2...N3.....
something that wont conflict with your ids but use something
that will let you know that it was null and number by you.

 

[samosa]

Thanks a bunch!
Good advise!!