A record description clause inserts text documenting a record definition into the CDD.
1 – Syntax Rules
o You must use the keyword DESCRIPTION and the text delimiters /*
and */ to insert one or more lines of text describing the record
into the DEFINE command.
2 – 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.
3 – 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.