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Corticon Studio: Rule Modeling Guide : Writing Rules to access external data : Inserting new records in a middle table

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Inserting 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 we have 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 may run into 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 table below highlights known limitations for combinations of entity identity (Application or Datastore) and association directionality (bidirectional or unidirectional):
* If com.corticon.reactor.engine.NoSyncAssoc property value is true, the order in which the association role assignments appear in the .new[…] operator may result in a situation where things appear to work but, in fact, the middle table is not updated properly in the database. This configuration should be avoided if Application Identity is used.