Table 1 is related by ID and...
Just so you know, that doesn't tell us as much as you might wish about your relationships. In WHICH table is the ID a unique identifier? Table 1 or Table 2? and the same goes with your description of the relationships between table 2 and 3.
But we may not need to know. FileMaker cannot match empty fields in a relationship, there has to be data in both fields in order for them to match. So instead of a null value, perhaps the only problem is comming up with a value in the match fields that will serve your needs that is not null.
Null values (zero-length strings, empty fields, etc.) cannot match across a relationship. i.e. NULL = NULL won't be considered a match. You'll need to use a second, calculated field that returns an actual value. e.g. with something like:
if( isempty( FirstField ) ; 0 ; 1 ) )
You'll need to make sure the field is always calculated (to save processor time, by default field calculations don't calculate if all referenced values are empty).
Then 0 = 0 is a match, 1 = 1 is a match, 1 = 0 or 0 = 1 are not matches.
Hope this helps!
It's the NULL=NULL not being a match is issue then... I was wondering if that was the issue.
So basically, I would be better off setting the first field to the value I don't want to match, and then have it pull what isn't equal?
That's a method that I have been able to make work in my solutions. But keep in mind that we know next to nothing about yours.
Thank you! That was it... I'm updating the table now. All that's left is to make sure that all the other fields are updated properly.