Q249836: PRB: Table Buffer Contains Uncommitted Changes on REQUERY()

Article: Q249836
Product(s): Microsoft FoxPro
Version(s): MACINTOSH:3.0b; WINDOWS:3.0,3.0b,5.0,5.0a,6.0
Operating System(s): 
Keyword(s): kbDatabase kbvfp300 kbvfp300b kbvfp500 kbvfp500a kbvfp600 KbDBFDBC kbGrpDSFox kbDSuppor
Last Modified: 08-JAN-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Macintosh, version 3.0b 
- Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0, 5.0a, 6.0 
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SYMPTOMS
========

The following error message appears when issuing a REQUERY() command against a
remote view:

  Table buffer for alias <view name> contains uncommitted changes

CAUSE
=====

This behavior occurs when a REQUERY() command is issued against a remote view
under the following conditions:

- Optimistic Table Buffering has been enabled.

- Changes have been made to one or more rows in the view.

- A TABLEUPDATE() or TABLEREVERT() command has not been issued.

RESOLUTION
==========

Issue a TABLEUPDATE() or TABLEREVERT() command before issuing a REQUERY()
command.

STATUS
======

This behavior is by design.

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

Steps to Reproduce Behavior
---------------------------

1. Create a program file named "BUFFDEMO" using the following code:

  CREATE TABLE test (Charfld c(10), Numfld N(10,4))
  CLOSE ALL

  CREATE DATA test
  CREATE CONNECTION testa CONNSTRING 'DRIVER=Microsoft Visual FoxPro Driver;' + ;
     'exclusive=no;SourceType=DBF;SourceDB='+SYS(5)+SYS(2003)

  ON ERROR DO errordemo IN buffdemo WITH MESSAGE()

  CREATE SQL VIEW myview CONNECTION testa ;
     AS SELECT * FROM test

  *Set View Properties
  DBSETPROP('MyView','View','SendUpdates',.T.)
  DBSETPROP('MyView','View','UpdateType',1)
  DBSETPROP('MyView','View','WhereType',3)
  DBSETPROP('MyView','View','BatchUpdateCount',1)
  DBSETPROP('MyView','View','UseMemoSize',255)
  DBSETPROP('MyView','View','FetchSize',100)
  DBSETPROP('MyView','View','MaxRecords',-1)
  DBSETPROP('MyView','View','Tables','test')
  DBSETPROP('MyView','View','Prepared',.F.)
  DBSETPROP('MyView','View','FetchMemo',.F.)
  DBSETPROP('MyView','View','CompareMemo',.F.)
  DBSETPROP('MyView','View','FetchAsNeeded',.F.)
  DBSETPROP('MyView','View','FetchSize',100)
  DBSETPROP('MyView','View','Comment',"")
  *DBSETPROP('MyView','View','ShareConnection',.T.)
  * Set Key and Updateable fields.
  DBSETPROP('MyView.Charfld','Field','KeyField',.T.)
  DBSETPROP('MyView.Charfld','Field','Updatable',.T.)
  DBSETPROP('MyView.Charfld','Field','UpdateName','test.charfld')
  DBSETPROP('MyView.Charfld','Field','DataType',"C(10)")
  DBSETPROP('MyView.Numfld','Field','KeyField',.F.)
  DBSETPROP('MyView.Numfld','Field','Updatable',.T.)
  DBSETPROP('MyView.Numfld','Field','UpdateName','test.numfld')
  DBSETPROP('MyView.Numfld','Field','DataType',"N(10,4)")

  SET MULTILOCKS ON

  USE myview
  =CURSORSETPROP('buffering',5)
  INSERT INTO myview VALUES ("test",1)
  *!* TABLEUPDATE(.T.)
  =REQUERY('myview')
  BROW
  ON ERROR
  CLOSE ALL

  PROCEDURE errordemo
  PARAMETER whatfailed
  messagebox(whatfailed,16+0,"Error")
  =TABLEREVERT(.T.)

2. Run the program file.

3. Note the message displayed in the message box.

4. Uncomment the TABLEUPDATE(.t.) command in BUFFDEMO.prg.

5. Run the program file.

6. Note that the remote view is updated and no error message appears.

REFERENCES
==========

For additional Information, query the Visual FoxPro product documentation for
the following topics:

- Buffered Updates (defined)

- REQUERY()

- TABLEUPDATE()

- TABLEREVERT()

(c) Microsoft Corporation 2000, All Rights Reserved. Contributions by John Desch,
Microsoft Corporation.


Additional query words: VIEW

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Keywords          : kbDatabase kbvfp300 kbvfp300b kbvfp500 kbvfp500a kbvfp600 KbDBFDBC kbGrpDSFox kbDSupport kbGrpDSODBC 
Technology        : kbHWMAC kbOSMAC kbVFPsearch kbAudDeveloper kbVFP300bMac kbVFP300 kbVFP300b kbVFP500 kbVFP600 kbVFP500a
Version           : MACINTOSH:3.0b; WINDOWS:3.0,3.0b,5.0,5.0a,6.0
Issue type        : kbprb

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