Application Overview: Data Model

The data model for the example application consists of a pair of Caché classes: Contact and PhoneNumber. The two classes form a parent-child relationship. This means that each Contact object can contain a set of PhoneNumber objects. Each PhoneNumber object must be contained in exactly one Contact object.

Contact contains the following four properties and a class query:

• ID — The object ID. Caché assigns values automatically. Values cannot be changed.

• Name — Represents a contact's name. The value can be any string.

• ContactType — Represents a contact's type. Values are restricted to “Business” and “Personal”.

• PhoneNumbers — Represents the collection of associated phone numbers.

• ByName — A class query that returns the ID and Name properties for all Contact instances with Name values matching the input parameter.

PhoneNumber contains the following four properties:

• ID — The object ID. Caché assigns values automatically. Values cannot be changed.

• PhoneNumberType — Represents the type of a phone number. Values are restricted to “Business”, “Home”, “Mobile”, and “Fax”.

• Number— Represents the actual number. The value can be any string.

• Contact — Represents the parent Contact object.