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Syntax Rules

Usage Notes

Example

CDD/Plus Dictionary Data Definition Language Utility FIELD_DESCRIPTION_CLAUSE — VMS CDD+_4.1A

 The optional field description clause inserts text documenting  field
 definitions into the CDD.


Additional information available:

Syntax RulesUsage NotesExample

Syntax Rules

  o  Use  the  text  delimiters  /*  and  */   without   the   keyword
     DESCRIPTION,  and  place  the  text  immediately before the field
     description statement of the field you want to document.

  o  You can use 8-bit characters in CDDL descriptions.


Usage Notes

  o  This clause provides a  way  to  associate  text  with  a  record
     description, providing a tool for documenting the sources of data
     and for describing the field structure of a record.   DESCRIPTION
     text  can  also aid in establishing record definition conventions
     and standards.

  o  You can also include comments in a CDDL source file by using  the
     exclamation   point  (!)  as  a  comment  delimiter.   Using  the
     DESCRIPTION clause is preferable to including  comment  lines  in
     the  source  file  because DESCRIPTION text is stored directly in
     the CDD.  CDDL/COPY_LIST copies DESCRIPTION clauses from template
     records,  but  does  not copy comments preceded by an exclamation
     point.  Also, you can display record-level DESCRIPTION text  with
     DMU's   LIST/ITEM=DESCRIPTION   command.    DMU's  EXTRACT/RECORD
     command extracts record- and  field-level  DESCRIPTION  text  but
     does not extract comments preceded by an exclamation point.


Example

 The  following  example  contains  DESCRIPTION  text  of  the  record
 definition as a whole, and of the elementary field ID.

 DEFINE RECORD CDD$TOP.CORPORATE.EMPLOYEE_LIST
     DESCRIPTION /* This record contains the employee master list,
                   and it is the source from which employee fields
                   in other record descriptions are copied. */.
     EMPLOYEE STRUCTURE.
         /* An employee's ID number is his or her social
         security number. */
         ID                       DATATYPE IS UNSIGNED NUMERIC
                                  SIZE IS 9 DIGITS.
         NAME STRUCTURE.
             LAST_NAME            DATATYPE IS TEXT
                                  SIZE IS 15 CHARACTERS.
             FIRST_NAME           DATATYPE IS TEXT
                                  SIZE IS 10 CHARACTERS.
             MIDDLE_INITIAL       DATATYPE IS TEXT
                                  SIZE IS 1 CHARACTER.
         END NAME STRUCTURE.
         ADDRESS                  COPY FROM
                                  CDD$TOP.CORPORATE.ADDRESS_RECORD.
         DEPT_CODE                DATATYPE IS UNSIGNED NUMERIC
                                  SIZE IS 3 DIGITS.
     END EMPLOYEE STRUCTURE.
 END EMPLOYEE_LIST RECORD.

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