You can add foreign keys to tables in Unified Modeling
Language (UML) class diagrams and Information Engineering (IE) or
Integration Definition for Information Modeling (IDEF1X) notation
diagrams.
The open database diagram must have a table with
a primary key.
To add a foreign key to a table:
- In the Palette, click Foreign Key.
- Click the table to which you want to add a foreign key
and drag to the target table that has a primary key.