Foreign Key Migration

Primary key attributes or columns automatically migrate from a parent to child entity or table when you connect them using a relationship. You can see the migrated attributes or columns in the child entity or table when you select the Foreign Key Designator (FK) and Show Migrated Attributes check boxes in the Diagram editor. You can also set these options by right-clicking the diagram background and using either the Entity Display or Table Display shortcut menu options.

• In an identifying relationship, the primary key attributes or columns of the parent entity or table migrate as primary key attributes or columns of the child. The child entity or table is dependent on the parent entity or table for its identity, and cannot exist without it.
• In a non-identifying relationship, the primary key attributes or columns of the parent entity or table migrate as non-key attributes or columns of the child. The child entity or table is not dependent on the parent entity or table for its identity, and can exist without it.

If two foreign keys have the same name, they unify when they migrate.

Note: When you delete a relationship, the automatic migration is reversed, and the migrated foreign keys are automatically removed from the child entity or table.

More information:

Unifying Relationships