IFRFLD (HLI function): Difference between revisions

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The conventions used on this page are described in [[HLI: Function call list#Function call notation conventions|Function call notation conventions]].
The conventions used on this page are described in [[HLI: Function summary#Function call notation conventions|Function call notation conventions]].


==Summary==
==Summary==

Revision as of 19:35, 13 July 2016

The conventions used on this page are described in Function call notation conventions.

Summary

Description
The IFRFLD call (REDEFINE FIELD) redefines one or more fields that have been previously defined for a Model 204 file. IFRFLD requires Model 204 file manager privileges.
Thread type
multiple cursor IFSTRT, single cursor IFSTRT
IFCALL function number
59

Syntax

IFRFLD(RETCODE,FIELD_DESC,FILE_SPEC)

Compile-only form
Not available
Execute-only form
Not available

Specify the parameters in the syntax order shown above.

Parameter Description
RETCODE [O,i,r] The Model 204 return code is the required first parameter. The code is a binary integer value.
FIELD_DESC [I,c,r] The field description is a required input parameter that specifies the name of the field to be redefined and a list of its new attributes. You may specify more than one field to be redefined. Specify the field description as a character string using the following format:

fieldname (attribute ...) [fieldname (attribute ...)];

where:

fieldname is required and specifies the name of the Model 204 field that is being redefined. Specify the name as a character string, up to 255 characters in length.

attribute is required and specifies a particular characteristic that controls how the field is used, stored, or accessed. You may specify more than one attribute, separating each by a comma or a blank. Specify only the attributes to be changed.

The attributes that can be specified using the IFRFLD call are identical to those that are used with the Model 204 REDEFINE command.

FILE_SPEC [I,s,o] The file specification is an optional input parameter for use only with a multiple cursor IFSTRT thread for specifying the name of the Model 204 file that contains the field to be redefined. Specify the name of the file as a short character string variable using the following format:

IN [FILE] filename

The specified file must be open on the thread; otherwise, the call is unsuccessful and Model 204 returns a completion code of 4.

Usage notes

Use the IFRFLD call to redefine a previously defined field in an open Model 204 file. Using the IFRFLD call allows a field definition to be altered without requiring that the file be reinitialized or reloaded. The IFRFLD call is valid only in file context, not for a group. The IFRFLD call is valid on all types of IFSTRT threads.

When FOPT=X'10' and the date/time stamp feature is installed, the IFRFLD function is supported for DTS files.

Note: The file context can change on a multiple cursor thread and, if the file specification parameter (FILE_SPEC) is omitted, IFRFLD redefines the field for the default file on the thread.

If the field being redefined has a security level, the Model 204 file manager must have field level security (FLS) access privileges. Note that changing a field's security level to 0 desecures the field. For information about field security, see Field-level security.

Note also that IFRFLD follows the same basic rules for specifying field attribute definitions as the Model 204 REDEFINE FIELD command.

Coding example (COBOL)

WORKING-STORAGE SECTION. 01 CALL-ARGS. 05 RETCODE PIC 9(5) COMP SYNC. 05 MODIFY PIC X(20) VALUE 'FIELDA (UP,LEVEL 0);'. . . . PROCEDURE DIVISION. . . . CALL "IFRFLD" USING RETCODE, MODIFY.