Overview of Copying Objects
You can select and copy one or more entities, tables, views, or drawing objects within the same model or to a different model.
Copying entities and other objects from a relational to a non-relational database is restricted in erwin Data Modeler (DM).
When you copy objects, you should consider the following:
- What happens to the relationships between tables or entities
- What happens to the foreign keys that migrate through these relationships
- What information is copied with a view
- How to maintain unique names
When you copy two or more entities or tables, any relationships between them are automatically copied, as are the foreign keys that are migrated 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 are transformed into owned attributes for the resulting entity. For example, if a child entity is copied but not its parent, foreign key attributes that migrated to the child from primary key or alternate key attributes in the parent entity are transformed into owned attributes to the child entity.
If you recreate the relationship later 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 and the "orphaned" ones match, and unifies them in the child object.
The current Unique Name setting is not enforced when you copy an object. If you want all objects in your model to have unique names, you must manually change the names in all copied objects.
Within a diagram, you can copy individual attributes or columns when you select them and use CTRL+drag and drop. If you simply select and drag attributes or columns, they are moved not copied.
|
Copyright © 2024 Quest Software, Inc. |