User manual

76 FileMaker Pro User’s Guide
Another example:
Self-joining relationships
A self-join is a relationship in which both match fields are defined in
the same table. Define a self-join to create relationships between
records in the same table. Use a self-join in a portal on a layout of the
current table to display a subset of data that is in the current table, such
as all the employees of each manager.
When you define a self-joining relationship in the relationships graph,
FileMaker Pro generates a second occurrence of the table upon which
you are basing the self-join. FileMaker Pro does this to prevent the
relationships graph from forming a cycle, which would make it
impossible to evaluate the relationship.
This relationship returns related records in Table G when the value in
Text Field G1 is the same as the value in Text Field G2.
For more information about the types of relationships, see Help.
Planning a relational database
For information about planning a relational database, see “Planning a
database” on page 39.
Working with the relationships graph
Use the relationships graph to create, change, and view the
relationships in your database file. The relationships graph lets you
duplicate tables and relationships, resize and align tables, and add text
notes. You can highlight tables that are connected to the selected table
via a 1-away relationship, and you can highlight tables that have the
same source table as the currently selected table. For more
information, see Help.
By default, the relationships graph displays all of the tables in your
current database file. You can add tables from other files, add more
than one occurrence of the same table to the graph, or remove tables
from the graph using the buttons at the bottom of the graph.
Creating relationships
To create a relationship:
1. With the database open, choose File menu > Define > Database.
2. In the Define Database dialog box, click the Relationships tab.
3. In the relationships graph, locate the two tables you will be using
for this relationship.
They can appear anywhere on the graph but they must be present on
the graph in order to create the relationship. For self-joining
relationships, locate the single table; FileMaker Pro will create the
second table occurrence for you.
If fields Contain values
These related records are
returned from Table F
Starting Date E 12/01/2005 12/02/2005
12/15/2005
12/17/2005
12/26/2005
Ending Date E 01/01/2006
Match fieldMatch field
Self-joining relationship