HP 3000 Manuals HP 3000 Manuals
Entity Types An entity type is a template for defining entities in the dictionary. System Dictionary comes with a set of built-in entity types, called core set entity types. The entity types of the core set are intended to be comprehensive enough to define most subsystem objects. You can also add new entity types if desired. In System Dictionary, the ability to add new entity types is restricted to users with a special capability (the extend scope-right). An entity type has two parts: * The entity type name. * A list of attributes associated with the entity type. You can think of entity types as categories. All IMAGE data base entities, for example, are grouped under the entity type IMAGE-DATABASE. You can also view an entity type as a qualifier. If a VPLUS form and an IMAGE data set both happen to be named CUSTOMERS, you can define the form as an entity of type FORM, and the data set as an entity of type IMAGE-DATASET. Since it is possible to have multiple entities with the same name, you must qualify an entity by specifying its entity type. You cannot delete one of the entity types involved with the relationship type unless you explicitly request that all the relationship types involving that entity type are to be deleted. Specifying Attribute Lists Entity types have attribute lists such that each entity of the type must have a value for each entity in the list. Every entity type has built-in attributes, called special attributes (special attributes are discussed later in this chapter). When you create an entity type, System Dictionary automatically associates these attributes with the new entity type. In addition, each entity type may have other attributes associated with it. For each attribute in an entity type's attribute list, there must be a corresponding attribute value assigned to each entity of that type. You can add attributes to an entity type's attribute list by creating type-attribute associations (discussed later). Creating and Accessing Entity Types You can create, delete, modify, and retrieve entity types. The actual instructions for doing these operations are located in other HP System Dictionary/XL manuals. Refer to the HP System Dictionary/XL SDMAIN Reference Manual (32256-90001) for instructions to do these operations with the System Dictionary user interface, or to the HP System Dictionary/XL Intrinsics Reference Manual (32256-90002), if using the System Dictionary intrinsics.