Coding Considerations › Syntax Format

Syntax Format

DDDL compiler input consists of statements arranged in a prescribed syntactical order. These statements reflect the logical organization of the dictionary by supporting standard IDD entity types, entity-type synonyms, entity types that support CA IDMS functions, and user-defined entity types.

All DDDL entity-type statements include the following five components:

• Verb
• Entity-type
• Entity-occurrence
• Optional clauses
• Period

Descriptions of these components follow.

Verb

The verb designates the requested function. One of the following verbs must accompany each DDDL entity-type statement:

• ADD establishes a new entity occurrence in the dictionary (see the table below for information about acceptable synonyms).
• MODIFY updates an existing entity occurrence with user-supplied options (see the table below for information about acceptable synonyms).
• DELETE removes an existing entity occurrence from the dictionary (see the table below for information about acceptable synonyms).

  For compatibility with CA IDMS SQL, the following verbs have been included as acceptable synonyms for ADD, MODIFY, and DELETE.

• REPLACE replaces an existing entity occurrence but preserves relationships established through other entity-type syntax.
• DISPLAY displays one or more existing entity occurrences, as follows:
  • In an online session, DISPLAY lists the requested definitions at the terminal. The user can edit the output and resubmit it to the DDDL compiler.
  • In batch mode, DISPLAY prints the requested definitions on the Integrated Data Dictionary Activity List.
• PUNCH lists one or more existing entity occurrences, as follows:
  • In an online session, PUNCH lists the requested definitions at the terminal. The user can edit the output and resubmit it to the DDDL compiler.
  • In batch mode, PUNCH writes the requested definitions to the SYSPCH output file or to an IDD module that has been defined as the PUNCH destination.

Entity Type

The entity type identifies the type of data that is the object of the specified verb. The DDDL compiler supports the following standard IDD entity types, entity-type synonyms, and CA IDMS components:

Entity Occurrence

The entity occurrence identifies a specific occurrence of the named entity type, entity synonym, or CA IDMS component. An entity occurrence consists of a name and an optional version number and language (attribute within the system-supplied class LANGUAGE), which permits the user to assign one name to multiple entity occurrences.

Optional Clauses

Optional clauses provide qualifying data for each entity occurrence. Once an entity occurrence has been defined, the user can extend its basic definition with optional data and comments and can associate the entity with other occurrences of the same entity type.

Period

A period signifies the end of the statement and is required in all DDDL statements. The period can directly follow the last word in the statement, can be separated from the last word by blanks, or can appear on a separate line. If specified in the SET OPTIONS statement (see SET OPTIONS Statement), a semicolon can also be used as an end-of-statement character.

Note: The end-of-statement character is not shown in the syntax diagrams for DDDL statements.

Order of Components

The verb, entity-type name, and entity-occurrence identification, which are required in all DDDL statements, must be specified in the order described above.

Optional clauses follow the entity-occurrence identification and can be specified in any order.

The period (or alternate character) must terminate each statement.

Example of Statement Components

The following example graphically illustrates the components of a typical DDDL statement:

 Verb
 │      Entity-type name
 │      │           Entity-occurrence identification
 │      │           │
 │      │           │            Optional clause
 │      │           │            │
 │      │           │            │           Terminating period
 │      │           │            │           │
 │      │           │            │           │
 │      │           │      ┌─────┴─────────┐ │
ADD  ELEMENT  DATE-OF-HIRE │PICTURE IS X(6)│ .

Exceptions to the syntax format rules are indicated in the syntax presentation.