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Parameters

Syntax Rules

Usage Notes

Example

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

 The DEFAULT_VALUE field attribute clause sets a default value  for  a
 field accessed by VAX DATATRIEVE.

Additional information available:

ParametersSyntax RulesUsage NotesExample

Parameters


 fixed_point_number

 dtrdv_quoted_string

      A VAX DATATRIEVE expression that is the default value.

Syntax Rules

  o  The quoted string (dtrdv_quoted_string)  or  fixed  point  number
     must  be  a  valid  VAX DATATRIEVE expression.  However, the CDDL
     compiler  does  not  check  for  correct  syntax.   It  is   your
     responsibility to provide a correct default value expression.

  o  You can use 8-bit characters in CDDL quoted strings.


Usage Notes

  o  The DEFAULT_VALUE clause, used with VAX DATATRIEVE,  serves  much
     the   same   purpose  as  the  INITIAL_VALUE  clause.   The  main
     difference is that the INITIAL_VALUE clause assigns a value to  a
     field when the field is first allocated, usually at compile time,
     but the DEFAULT_VALUE clause assigns a value to a field each time
     the record is stored without an explicit value assigned to it.

  o  Only VAX DATATRIEVE supports  the  DEFAULT_VALUE  clause.   Other
     language processors ignore it.


Example

 The following example assigns a  DEFAULT_VALUE  of  0  to  the  field
 TOTAL_PRICE.

 TOTAL_PRICE             DATATYPE IS VIRTUAL FIELD
                         COMPUTED BY DATATRIEVE AS
                             "UNIT_PRICE * QUANTITY"
                         DEFAULT_VALUE FOR DATATRIEVE IS 0.

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