Insert new records in a middle table

In relational databases, many-to-many relationships are modeled using a "middle" table (also known as an intersection table). Assume two tables named A and B, and they have a many-to-many relationship. A third or middle table named AB has a many-to-1 relationship with both A and B.

A many-to-many association between two entities in the Vocabulary can be mapped to such a middle table. Therefore, table AB does not need to correspond to a specific entity in the Vocabulary. However, should the middle table contain additional business fields, then it must have a corresponding entity in the Vocabulary. In such a situation, attempting to create a new record/row in table AB using rules can cause limitations depending on:

• The cardinalities of the associations between AB and A, and AB and B
• The identity strategy used for A, B, and AB

The following table highlights known limitations for combinations of entity identity (Application or Datastore) and association directionality (bi directional or uni directional):

The one uni / one bi configuration should be avoided when Application Identity is used.