Microsoft KB Archive/191344

= PRB: Base Table Fields Changed with Remote View =

Article ID: 191344

Article Last Modified on 3/3/2005

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APPLIES TO


 * Microsoft Visual FoxPro 5.0 Standard Edition
 * Microsoft Visual FoxPro 5.0a
 * Microsoft Visual FoxPro 6.0 Professional Edition
 * Microsoft Data Access Components 2.5

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This article was previously published under Q191344



SYMPTOMS
When issuing a REQUERY command against a remote view, while a second remote view is being USEd, the following error message appears:

Base table fields have been changed and no longer match view fields. View field properties cannot be set.



CAUSE
This behavior occurs when two or more views are defined with the following attributes:


 * The views were created using the same named connection to a remote data source.
 * The views were created using the SHARED clause in the CREATE SQL VIEW command.
 * The Prepared property of the views is set to .T.



RESOLUTION
  Do not include the SHARED clause in the CREATE SQL VIEW command used to create the remote view: CREATE SQL VIEW "MYVIEW1" ; REMOTE CONNECT "CONN1" ; AS SELECT * ; FROM mytable_a DBSETPROP('MYVIEW1', 'View', 'Prepared', .T.) CREATE SQL VIEW "MYVIEW2" ; REMOTE CONNECT "CONN1" ; AS SELECT * ; FROM mytable_b DBSETPROP('MYVIEW2', 'View', 'Prepared', .T.)   Create a separate connection for each of the views: CREATE CONNECTION CONN1 DATASOURCE 'CONNECT' USERID 'SA' PASSWORD '' CREATE CONNECTION CONN2 DATASOURCE 'CONNECT' USERID 'SA' PASSWORD '' CREATE SQL VIEW "MYVIEW1" ; REMOTE CONNECT "CONN1" SHARED ; AS SELECT * ; FROM mytable_a DBSETPROP('MYVIEW1', 'View', 'Prepared', .T.) CREATE SQL VIEW "MYVIEW2" ; REMOTE CONNECT "CONN2" SHARED ; AS SELECT * ; FROM mytable_b DBSETPROP('MYVIEW2', 'View', 'Prepared', .T.)   Use the default PREPARED property: CREATE SQL VIEW "MYVIEW1" ; REMOTE CONNECT "CONN1" ; AS SELECT * ; FROM mytable_a USE MYVIEW1 IN 0 CREATE SQL VIEW "MYVIEW2" ; REMOTE CONNECT "CONN1" ; AS SELECT * ; FROM mytable_b 



STATUS
Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.



MORE INFORMATION
The default values for View properties are listed in the following table:   Property Name            Default Value --  SendUpdates              .F. (False) UpdateType              1 SQL Update WhereType               3 Key and Modified Fields BatchUpdateCount        1 UseMemoSize             255 FetchSize               100 FetchMemo               .T. (True) MaxRecords              -1 (All) Tables                  Database Container and Table Name Comment                 Null String Prepared                .F. (False) CompareMemo             .T. (True) FetchAsNeeded           .F. (False)

Steps to Reproduce Behavior
  Use the following code snippet to create a database container and two tables that will serve as a data source: CREATE DATABASE TESTODBC CREATE TABLE mytable_a (       FLD_A I NULL, FLD_C C(15) NULL) CREATE TABLE mytable_b (       FLD_B I NULL,FLD_A I NULL,FLD_C C(15) NULL) INSERT INTO mytable_a (FLD_A,FLD_C) VALUES (10452,'TEST1') INSERT INTO mytable_b (FLD_B,FLD_A,FLD_C) VALUES (1,22345,'TEST1') CLOSE ALL </li> Open the 32-bit ODBC Data Source Administrator and create an ODBC data source called "CONNECT" with a path to the Testodbc.dbc file, created in step 1.</li>  Create a .prg file named Odbcdemo.prg, using the following code: * Begin Code

CLOSE ALL SET SAFETY OFF CREATE DATABASE odbcdemo CREATE CONNECTION CONN1 DATASOURCE 'CONNECT' USERID 'SA' PASSWORD '' CREATE SQL VIEW "MYVIEW1" ; REMOTE CONNECT "CONN1" SHARED ; AS SELECT * ; FROM MYTABLE_A DBSETPROP('MYVIEW1', 'View', 'Prepared', .T.) CREATE SQL VIEW "MYVIEW2" ; REMOTE CONNECT "CONN1" SHARED ; AS SELECT * ; FROM MYTABLE_B DBSETPROP('MYVIEW2', 'View', 'Prepared', .T.) CLOSE ALL OPEN DATA odbcdemo USE MYVIEW1 USE MYVIEW2 IN 0 =REQUERY('MYVIEW1') && FAILS HERE. =REQUERY('MYVIEW2') =REQUERY('MYVIEW1') =REQUERY('MYVIEW2') </li>  From the command line type the following: DO ODBCDEMO NOTE: Observe that the code fails during the attempt to issue a REQUERY command on MYVIEW1. </li> Edit the Odbcdemo.prg file and modify the code to reflect each of the preceding workarounds. Run the program after each change.</li></ol>

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