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Associating Entity Occurrences

IDD supports relationships between entity occurrences to enable the dictionary to correctly represent relational facts about the data resource. An example of such a relationship is the association between a user and a system.

Standard Relationships

The DDDL compiler establishes standard entity-occurrence relationships through the clauses shown in the following table.

More information: For more information on these clauses, see Entity-Type Syntax.

Clause

What it does

USER

Defines the relationship between an entity occurrence and its users. This clause is valid in all entity types except CLASS, LOAD MODULE, MESSAGE, and USER and is described under Securing the Dictionary, earlier in this chapter.

WITHIN SYSTEM

Defines the relationship between a destination, line, logical terminal, map, module, physical terminal, process, program, qfile, queue, table, or task and a system or subsystem. Syntax for the WITHIN SYSTEM clause appears in the individual entity-type syntax in Chapter 4.

Nesting clauses

Expresses hierarchical relationships between two users, systems, files, elements, or programs.

Standard Nesting Clauses

The standard nesting clauses are as follows:

Entity type

Clause

ELEMENT

SUBORDINATE ELEMENT

FILE

RELATED FILE

PROGRAM

PROGRAM CALLED

SYSTEM

WITHIN SYSTEM

USER

WITHIN USER

These clauses are described in detail within the applicable entity-type statement in Chapter 4.

User-defined Relationships

The DDDL compiler also supports user-defined entity-occurrence relationships through the following:

Relational keys and attribute/entity relationships are discussed separately in this section.