
Natural for OpenVMS	Version 6.3.12 for OpenVMS	SEARCH CONTENTS \| PDF BOOKS \| HOME UP PREV NEXT

— Statements —

Redefinition

The redefinition option is used with DEFINE DATA LOCAL, DEFINE DATA PARAMETER, DEFINE DATA INDEPENDENT, DEFINE DATA CONTEXT and DEFINE DATA OBJECT.

The redefinition option has the following syntax:

`REDEFINE` `field-name`	`level`	`rgroup`
		`rfield` (`format-length` [/`array-definition`])
		`FILLER` `nX`

This document covers the following topics:

Function
Restrictions
Syntax Description

For an explanation of the symbols used in the syntax diagram, see Syntax Symbols.

Function

A redefinition may be used to redefine a group, a view, a DDM field or a single field/variable (that is a scalar or an array).

Notes:

A redefinition of a view or a DDM field is not applicable to a parameter-data-definition.
Unicode fields should not be redefined as alphanumeric (A) or numeric (N) fields.

See also Redefining Fields in the Programming Guide.

Restrictions

Handles, X-arrays and dynamic variables cannot be redefined and cannot be contained in a redefinition clause.
A group that contains a handle, X-array or a dynamic variable can only be redefined up to - but not including or beyond - the element in question.

Syntax Description

Syntax Element	Description
`field-name`	Name of Field to be Redefined: The name of the group, view, DDM field or single field that is being redefined.
`level`	Level Number of Field being Redefined: Level number is a 1- or 2-digit number in the range from 01 to 99 (the leading zero is optional) used in conjunction with field grouping. Fields assigned a level number of 02 or greater are considered to be a part of the immediately preceding group, which has been assigned a lower level number.
`rgroup`	Name of Resulting Group: The name of the group resulting from the redefinition. Note: In a `redefinition` within a `view-definition`, the name of `rgroup` must be different from any field name in the underlying DDM.
`rfield`	Name of Resulting Field: The name of the field resulting from the redefinition. Note: In a `redefinition` within a `view-definition`, the name of `rfield` must be different from any field name in the underlying DDM.
`format-length`	Format/Length of Resulting Field: The format and length of the resulting field (`rfield`).
`array-definition`	Array Dimension Definition: With an `array-definition`, you define the lower and upper bounds of dimensions in an array-definition. For further information, see Array Dimension Definition.
`FILLER nX`	Filler Byte Definition: With this notation, you define `n` filler bytes - that is, segments which are not to be used - in the field that is being redefined. The definition of trailing filler bytes is optional.

Examples of REDEFINE Usage

Example 1:	Example 2:	Example 3:
DEFINE DATA LOCAL 01 #VAR1 (A15) 01 #VAR2 02 #VAR2A (N4.1) INIT <0> 02 #VAR2B (P6.2) INIT <0> 01 REDEFINE #VAR2 02 #VAR2RD (A10) END-DEFINE ...	DEFINE DATA LOCAL 01 MYVIEW VIEW OF STAFF 02 NAME 02 BIRTH 02 REDEFINE BIRTH 03 BIRTH-YEAR (N4) 03 BIRTH-MONTH (N2) 03 BIRTH-DAY (N2) END-DEFINE ...	DEFINE DATA LOCAL 1 #FIELD (A12) 1 REDEFINE #FIELD 2 #RFIELD1 (A2) 2 FILLER 2X 2 #RFIELD2 (A2) 2 FILLER 4X 2 #RFIELD3 (A2) END-DEFINE ...

Example 1:

Example 2:

Example 3:

   DEFINE DATA LOCAL
     01 #VAR1 (A15)
     01 #VAR2
        02 #VAR2A (N4.1) INIT <0>
        02 #VAR2B (P6.2) INIT <0>
     01 REDEFINE #VAR2
        02 #VAR2RD (A10)
   END-DEFINE
   ...

   DEFINE DATA LOCAL
   01 MYVIEW VIEW OF STAFF
      02 NAME
      02 BIRTH
      02 REDEFINE BIRTH
         03 BIRTH-YEAR  (N4)    
         03 BIRTH-MONTH (N2)
         03 BIRTH-DAY   (N2)
   END-DEFINE
   ...

   DEFINE DATA LOCAL           
   1 #FIELD (A12)
   1 REDEFINE #FIELD
     2 #RFIELD1 (A2)
     2 FILLER 2X
     2 #RFIELD2 (A2)
     2 FILLER 4X
     2 #RFIELD3 (A2)
   END-DEFINE
   ...

SEARCH CONTENTS | PDF BOOKS | HOME UP PREV NEXT