Database Reference
In-Depth Information
Figure 14-2. FileMaker keeps you from creating any relationship that would introduce ambiguity
into the Relationships graph. If you try to make a relationship between two TOs that are already re-
lated, you'll see the Add Relationship dialog box.
TIP
The Add Relationship and Edit Relationship dialog boxes are two of the many places where
FileMaker itself doesn't make the all-important distinction between tables and table occurrences. If
you're not sure, take a look at the items in the Table pop-up menu. If you see names like In-
voice_currentJob, or if the Table pop-up menu lists more names than you know you have tables, you
can be sure that you're looking at a list of TOs, and
not
tables themselves.
WORKAROUND WORKSHOP: WHEN DRAGGING DOESN'T DO IT
Dragging isn't the only way to create a new relationship on the graph. Some folks like to click the
Add Relationship button to start with a clean Add Relationship window. It's just like Edit Relation-
ship, except that since it starts out blank, the Table pop-up menu at the top of the window isn't
grayed out. That is, you have to start out by selecting the two table occurrences you want to relate.
Then you can select your key fields and all the other options that get the relationship job done.
Using this method doesn't circumvent the rule forbidding ambiguity or circularity (
Avoiding Ambi-
guity
)
. But say you're trying to create a new relationship between the Invoices table and the Cus-
tomers table by using the Add Relationship window. In that case, you'll get all the way through the
process of selecting tables and key fields and operators before FileMaker can warn you that the rela-
tionship won't work and you need a new table occurrence.
You might wish the warning had been offered a little earlier in the process. But you do have control
over which table gets the new occurrence. FileMaker creates the new TO for the table listed on the
right side of the window. When you drag, FileMaker uses the direction you drag to decide which
table to create a new occurrence for. That is, if you drag from Customers to Invoices, FileMaker will
create a new TO for Invoices.
