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Q129980: INFO: Private Data Session Resets the Environment

Article: Q129980
Product(s): Microsoft FoxPro
Version(s): 
Operating System(s): 
Keyword(s): kbenv kbnokeyword kbvfp300 kbvfp500 kbvfp600
Last Modified: 10-AUG-1999

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 3.0, 5.0, 6.0 
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SUMMARY
=======

A data session is a set of work areas used by a form, form set, report, or
label. This article explains the use of a private data session in a form or form
set and the settings it affects.

MORE INFORMATION
================

When a form or a form set is loaded, it uses the Default Data session by
default. This means that the work areas and all settings are global. You can
however define private data sessions with your form and form sets by modifying
the DATASESSION property of the form.

When a data session is private, work areas are private to the object. Thus, two
forms can use the same tables, and the record pointer can move independently in
both forms. This can be particularly useful with the Visual FoxPro object model,
where multiple instances of the same object can exist and you might need to
access multiple records in the same table.

In addition to scoping work areas, a private data session of a form affects some
SET commands that control the environment. Private data sessions use:

- The default Visual FoxPro settings.

Modifying these settings in a program or in the Command window has no effect on
the SET commands if a form has a PRIVATE data session. The following SET
commands are scoped to private data sessions:

  SET ANSI
  SET AUTOSAVE
  SET BLOCKSIZE
  SET CARRY
  SET CENTURY
  SET COLLATE
  SET CONFIRM
  SET CURRENCY
  SET DATABASE
  SET DATE
  SET DECIMALS
  SET DELETED
  SET DELIMITERS
  SET EXACT
  SET EXCLUSIVE
  SET FIELDS
  SET FIXED
  SET LOCK
  SET MARK TO
  SET MEMOWIDTH
  SET MULTILOCKS
  SET NEAR
  SET NULL
  SET PATH
  SET POINT
  SET REFRESH
  SET REPROCESS
  SET SAFETY
  SET SEPARATOR
  SET TALK
  SET UNIQUE

If you need to modify the default settings that are used by a form with a private
data session, you can do the following:

- If you have a Data Environment and the AUTOLOADTABLES property is set to .T.,
  you can add your SET code in the BEFOREOPENTABLES event handler. This event
  is executed before the tables are opened. The BEFOREOPENTABLES event is
  executed before the Load event of the Form Set. For example, if the default
  setting for TALK is ON, and you want to modify this setting while your form
  is running, type the following in the Method for the BEFOREOPENTABLES event:

        SET TALK OFF

- If you do not have a DataEnvironment associated with a form, place the code
  in the LOAD event of the form.

Additional query words:

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Keywords          : kbenv kbnokeyword kbvfp300 kbvfp500 kbvfp600 
Technology        : kbVFPsearch kbAudDeveloper kbVFP300 kbVFP500 kbVFP600
Issue type        : kbinfo

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