PRB: Table Buffer Contains Uncommitted Changes on REQUERY()

• Microsoft Visual FoxPro for Macintosh, version 3.0b
• Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0, 5.0a, 6.0

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()

Additional query words: VIEW

Keywords : kbDatabase kbVFp300 kbVFp300b kbVFp500 kbVFp500a kbVFp600 KbDBFDBC kbGrpFox kbDSupport kbGrpODBC
Version : MACINTOSH:3.0b; WINDOWS:3.0,3.0b,5.0,5.0a,6.0
Platform : MACINTOSH WINDOWS
Issue type : kbprb