Database Reference
In-Depth Information
FREQUENTLY ASKED QUESTION: FILEMAKER'S SIXTH SENSE: CROW'S
FEET
I haven't done anything to tell FileMaker what kind of relationships I created. How does it know
where to put the crow's feet?
You never have to tell FileMaker what type of relationship to create because it doesn't really matter.
The work FileMaker performs to deal with a one-to-many relationship is no different from what it
does for a one-to-one, so it doesn't care about the distinction.
However, it's useful to you as the database designer to know what kind of relationships you have.
So as a special service to you, FileMaker tries to figure out where the crow's feet go. It helps you
decide whether an invoice should have room for one line item or a whole list of them, for example.
So FileMaker assumes every end of every line needs a crow's foot unless it finds evidence to the
contrary, like the following:
▪ The field used in the relationship is a serial number.
▪ The field used in the relationship has the “Unique validation” option turned on.
A line that connects to a field that meets either of these conditions does
not
get a crow's foot at that
end. Since all your primary keys are serial numbers, FileMaker has no trouble figuring out where to
leave off the crow's feet.
