When you copy two or more entities or tables, any relationships between them are automatically copied, as are the foreign keys that migrate through these relationships.
However, if you copy only one entity or table in a relationship, the relationship is not copied. As a result, foreign key attributes or columns become owned attributes or columns in the resulting entity or table. For example, if a child entity is copied but not its parent, foreign key attributes that migrated to the child through the relationship become owned attributes of the child entity.
Later, if you recreate the relationship and cause the same attributes or columns to migrate to the child entity or table as a foreign key, the program recognizes that the new foreign key attributes or columns are duplicates. Before adding the duplicate objects, you are asked if you want to unify, rename, or rolename them.
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