Title: Resolve many-to-many relationships.
Course: Database Design and Management (Oracle) (10052) > Section: Applying Design Concepts to Database Models

A many-to-many relationship can be modeled; however, it cannot be implemented in a relational database because it violates data integrity. A many-to-many relationship is reduced to two one-to-many relationships with an intersecting entity. Create a new entity that is positioned between the existing two entities.

Resolution is accomplished by following these steps:

1. Determine the name of an intersecting entity (name using a combination of the two many-to-many names if necessary).
2. Define the first one-to-many relationship and put the many on the intersecting entity.
3. Add the other relationship (which should be the original relationship between the two entities without the cardinality). Define the second one-to-many relationship, again with the many on the intersecting entity.