4.2.3. Many-to-Many Associations

The many-to-many association implies that multiple records in one table are related to multiple records in another table. The joining table will store primary keys of both related entities. Optionally, this table may contain additional columns.

Depending on whether you need additional fields in the joining table, you can implement many-to-many relationship with an additional entity or without it. The following examples illustrate both approaches.