In a many to many relationship, a collection of records in one table occurrence can share a relationship to many records in another table occurrence. In this example, we have a link between a students table to a classes table by using a Class ID field on both sides. One method of having a many to many relationship in FileMaker is to use a join table. So you actually have 3 tables involved in making a many to many relationship between two tables. We don't use that setup here!
In this example, we only have the two tables but in the students table, we are using a multiple line key field. This means we are putting in key data with a carriage return between them. FileMaker will see this as two different data keys.
Take a look at the students layout and you will see how the fk_class_id field has two key data strings separated by a carriage return. Since we included a carriage return between each ID ... we were able to link to multiple class records. You can do the same thing in any file ... so you can have many to many relationships all over the place.
The file can be downloaded by clicking (here)
© 2010 - Dwayne Wright - dwaynewright.com
The material on this document is offered AS IS. There is NO REPRESENTATION OR WARRANTY, expressed or implied, nor does any other contributor to this document. WARRANTIES OF MERCHANT ABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY DISCLAIMED. Consequential and incidental damages are expressly excluded. FileMaker Pro is the registered trademark of FileMaker Inc.