HP System Dictionary/XL General Reference Manual Vol 1 (32256-90004)
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Specifying Entity Types
Entity types are dictionary categories that you must specify when you create, delete, modify, or retrieve an
entity. When you create or access an entity, you must specify an entity type that already exists in the
dictionary. If the entity type you specify does not exist, the access fails. System Dictionary has a built in
set of entity types, called core set entity types. You can also add your own extended set of entity types.
Any entity type in the core set or extended set is available to all users of the dictionary. The core set and
extended set are discussed in Chapter 6 of this manual.
An example of entities and entity types is illustrated in Figure 3-3. The top half of the figure shows the
entity types (as ellipses) and the attributes of those entity types (as boxes). The lower half shows specific
entity occurrences (CORP and R&D) of the respective entity types, and the attribute values of the
attributes associated with them.
Figure 3-3. Entity Types vs. Entities
Entity Attribute Values
Entities have attribute values that define and characterize the entity definition itself (when it was created
in the dictionary, the owner, etc.) or that describe the entity's tangible object. Table 3-1 shows some
sample entities of the entity type IMAGE-DATASET. Each entity in the table refers to a data set in an
IMAGE data base. In the first column of the table are the entity names. The other columns contain values
for the attributes SCOPE-OWNER, DATE-CREATED, and IMAGE-DATASET-TYPE. The SCOPE-