Working with Data Models › Working with Transformations › Using a Transformation to Resolve a Many-to-Many Relationship

Using a Transformation to Resolve a Many-to-Many Relationship

You can apply a transformation and resolve a many-to-many relationship in a logical model (or the logical side of a logical/physical model). To avoid design problems that may be caused by many-to-many relationships, database designers frequently add associative entities to act as a connection for two ambiguously related entities. If you apply a transformation and automatically insert an associative entity between the two entities involved in a many-to-many relationship, you can change the relationship into a series of one-to-many relationships and use the new relationships to clarify how the data model works.

A Many-to-Many transformation can be applied to an existing many-to-many relationship in either a logical-only model, or the logical view of a logical/physical model.

Result of Resolving a Many-to-Many Relationship

When you apply a Many-to-Many transformation, the association entity and its relationships are preserved and the many-to-many relationship is deleted. No attribute or column is affected by the transformation. The preserved association entity and its relationships can be viewed in either the logical or physical model.

If you create a Many-to-Many relationship between entities on the logical side and automatically insert an associative table between the two tables involved in a many-to-many relationship, you can change the relationship into a series of one-to-many relationships and use the new relationships to clarify how the data model works.