Simple One-to-One maps a repository item to a single table row. It includes just a primary table, with no joins with other tables. This is the simplest case.

One-to-One with Auxiliary Table maps a repository item to a primary table and an auxiliary table (a one-to-one relationship). Each user has a job title and function.

One-to-Many with an Array maps a repository item to a primary table and a multi-value table with an array property. This demonstrates a one-to-many relationship. The multi table, named subjects_tbl, contains a list of a user’s favorite subjects (simple strings). When using an array or list type property, the multi table requires a multi-column-name attribute (in this example, seq_num) to ensure that the ordering of the multi-values are maintained.

One-to-Many with a Set maps a repository item to a primary table and a multi-value table with a set type property. This is another example of one-to-many relationship. Because a set is used, a multi-column-name attribute is not required.

One-to-Many with a Map maps a repository item to a primary table and a multi-value table with a map property. When using a map type property, the multi table requires a multi-column-name attribute (in this example, card_key). This column contains keys that uniquely identify each of the multi-values. For example, each user has many credit cards; the keys are strings that identify each of the user’s cards (like business card, frequent flyer card, personal card.

One-to-Many Mapping to Other Repository Items maps a one-to-many relationship. It defines two item types, user and address. Each user can have many addresses.

Ordered One-to-Many demonstrates an ordered one-to-many relationship with a list type property. It defines two item types, author and book. Each author can have many books, and the order of the books is considered significant.

Many-to-Many maps a many-to-many relationship. It defines two item types, user and address. Each user can have many addresses. Many users may live at the same address.

Multi-Column Repository IDs demonstrates the use of composite repository IDs.