Article ID: 191344
Article Last Modified on 3/3/2005
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
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:
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
- 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.
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')
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.
- Edit the Odbcdemo.prg file and modify the code to reflect each of the preceding workarounds. Run the program after each change.
REFERENCES
For additional information, please see the following article in the Microsoft Knowledge Base:
178760 HOWTO: Alter the Properties of a View at Run Time
Keywords: kbdatabase kbprb kbpending kbcode KB191344