Deciding where to place related fields
You can place fields from related tables either directly on layouts or in portals:
Directly on layouts: Place related fields directly on a layout to display data from the first related record, even when there are more than one related record that match the criteria of the relationship. (The first related record that is displayed is determined by whether the relationship specifies a sort order.)
In portals: Place related fields within a portal on a layout to display data from all related records that match the criteria of the relationship.
For example, you might do the following on an Invoice layout in an Invoices database:
How FileMaker Pro evaluates references to related fields in portals
When you place a related field in a portal, FileMaker Pro uses one of two starting points to evaluate the related data to display: the record in the portal’s table, or the record in the layout’s table. The starting point is significant because it affects the related data that the field displays.
FileMaker Pro determines which starting point to use based on the path of relationships between two tables in the relationships graph:
If the path of relationships from the layout’s table to the field’s table includes the portal’s table, the record in the portal’s table is the starting point. Otherwise, the record in the layout’s table is the starting point.
For example, the following relationships graph shows a school enrollment database. It contains tables for teachers, classes, and students, and an enrollment table to indicate which students are in each class. There is also an advisors table (another occurrence of the teachers table) which assigns a faculty advisor to each student.
Example of relationships for five tables in a school enrollment database
Consider the following layout, which displays the enrolled students in a class. The layout’s table is Classes, and the portal’s table is Students.
Example of a portal on a layout
The table below describes how FileMaker Pro determines the starting points for four fields placed in this portal from different tables.
In addition to fields placed in a portal, FileMaker Pro uses this method to determine the starting point for other references to fields in portals:
Value lists: when a value list is defined to include only related values from a field, and a field in a portal is formatted to display this value list. (The starting point determines the values displayed in the value list.)
Calculations: when scripted calculations refer to fields while a portal is active.
Usually, FileMaker Pro determines the correct related data to display. However, you can change the starting point by modifying the relationships graph to include other tables and relationships, and then changing the related fields referenced in the portal.
Related topics:
Adding fields to a layout
Placing and removing fields on a layout
Creating portals to display related records
Working with related tables and files
Example of a value list that includes only related field values