When you add an identifying or non-identifying relationship, the parent key or the alternate key migrates to the child entity as a foreign key. If an attribute in the child entity exists with the same name as the foreign key, you are prompted to resolve the duplication. Click one of the following options:
Unifies the identical attributes by unifying the owned attribute and the foreign key in the child entity. If you delete the relationship, you also delete the only instance of the attribute in the child entity.
Lets you enter a new name for the identical child attribute but the foreign key keeps the name it inherits from the parent key. If you delete the relationship, the foreign key is deleted but the renamed attribute still exists in the child.
Lets you enter a rolename for the foreign key that describes its purpose in the child entity. If you delete the relationship, the foreign key is deleted to which you assigned the rolename, but the owned attribute still exists in the child.
Note: By default, a column in the physical model inherits its name from the corresponding attribute in the logical model. For this reason, only the logical model is checked to determine if a duplicate attribute exists in an entity. Unless you manually change the corresponding column name in the physical model, the migrating key option that you choose for the logical model automatically applies to the physical model.
|
Copyright © 2017 erwin Inc.
All rights reserved.
|
|