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Q262067: BUG: RStoCursor in Vfpcom.dll Fails with Certain Data Types

Article: Q262067
Product(s): Microsoft FoxPro
Version(s): WINDOWS:3.0,3.0b,5.0,5.0a,6.0
Operating System(s): 
Keyword(s): kbCOMt kbDatabase kbOOP kbvfp300 kbvfp300b kbvfp500 kbvfp500a kbvfp600 KbDBFDBC kbGrpDS
Last Modified: 05-AUG-2000

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0, 5.0a, 6.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

Microsoft Visual FoxPro developers often make use of the VFPCOM Utility, which
is available for download from the Microsoft Visual FoxPro Web site. Among other
things, this sample allows users to convert an ADO recordset into a FoxPro
cursor through its RSToCursor() method.

When you attempt to create a cursor from an ADO recordset by using the
RSToCursor() method, the numeric, float, and Double data types are not converted
properly. This behavior results in a -10 return code from the object, and the
FoxPro cursor is not created.

Additional information on the Vfpcom sample and its error codes may be found in
the "References" section later in this article.

RESOLUTION
==========

There is a Microsoft Visual FoxPro RS2DBF function inside of the program named
RS2DBF.PRG that converts an ADO recordset to a Visual FoxPro cursor and retains
numeric, float, and Double data types.

More information and a download point can be found at this Microsoft Web site:

  RS2DBF.EXE

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

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

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

1. If you have not done so already, download and unzip the VFPCOM Utility from
  the Microsoft Visual FoxPro samples Web site.

2. Follow the instructions in the "Installation and Setup" section of the
  Vfpcom.htm file that accompanies the sample.

3. Copy the following code to a new program, and then run it to demonstrate the
  problem. Note that there is a return value from the Vfpcom.dll of -10
  ("Failed to create Fox cursor"). This occurs when the utility tries to
  convert an ADO Recordset with one float, numeric or double field, into a Fox
  cursor.

  ******************************* START CODE *******************************
  CLEA
  LOCAL loVFPCOM, loRS, lnError

  loVFPCOM = CREATEOBJECT("vfpcom.comutil")
  IF VARTYPE(loVFPCOM) # 'O' OR ISNULL(loVFPCOM)
  	MESSAGEBOX("Problem creating VFPCOM Object. Exiting")
  	RETURN .F.
  ENDIF

  *~ Let's try with a cursor with one, NUMERIC field
  MAKE_CURSOR('NUMERIC')
  ? "*** NUMERIC FIELD TEST ***"
  loRS = CREATEOBJECT("adodb.recordset")
  lnError = loVFPCOM.CURSORTORS(loRS)
  ? "CursorToRs Err Code for table with 1 NUMERIC field... ", TRANSFORM(lnError)
  lnError = loVFPCOM.RSTOCURSOR(loRS, "test")
  ? "RStoCURSOR Err Code for table with 1 NUMERIC field... ",  TRANSFORM(lnError)
  ?
  loRS = NULL
  RELEASE loRS
  *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  *~ Let's try with a cursor with one, FLOAT field
  MAKE_CURSOR('FLOAT')
  ? "*** FLOAT FIELD TEST ***"
  loRS = CREATEOBJECT("adodb.recordset")
  lnError = loVFPCOM.CURSORTORS(loRS)
  ? "CursorToRs Err Code for table with 1 FLOAT field... ", TRANSFORM(lnError)
  lnError = loVFPCOM.RSTOCURSOR(loRS, "test")
  ? "RStoCURSOR Err Code for table with 1 FLOAT field... ",  TRANSFORM(lnError)
  ?
  loRS = NULL
  RELEASE loRS
  *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  *~ Let's try with a cursor with one, DOUBLE field
  MAKE_CURSOR('DOUBLE')
  ? "*** DOUBLE FIELD TEST ***"
  loRS = CREATEOBJECT("adodb.recordset")
  lnError = loVFPCOM.CURSORTORS(loRS)
  ? "CursorToRs Err Code for table with 1 DOUBLE field... ", TRANSFORM(lnError)
  lnError = loVFPCOM.RSTOCURSOR(loRS, "test")
  ? "RStoCURSOR Err Code for table with 1 DOUBLE field... ", TRANSFORM(lnError)
  ?
  loRS = NULL
  RELEASE loRS
  *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  *~ Clean-up
  loRS = NULL
  loVFPCOM = NULL
  RELEASE loRS, loVFPCOM

  *~~~~~~~ PROCEDURES ~~~~~~~~~~~~~

  PROCEDURE MAKE_CURSOR(lcFldType)
  	DO CASE
  		CASE lcFldType = 'NUMERIC'
  			CREATE CURSOR test(n_num N(5))

  		CASE lcFldType = 'FLOAT'
  			CREATE CURSOR test(floatfld F(10))

  		CASE lcFldType = 'DOUBLE'
  			CREATE CURSOR test(dobfld B(2))
  	ENDCASE

  	LOCAL i
  	FOR i = 1 TO 10
  		INSERT INTO test VALUES(i)
  	NEXT i
  ******************************* END CODE *******************************

REFERENCES
==========

For additional information, click the article numbers below to view the articles
in the Microsoft Knowledge Base:

  Q235985 INFO: Error Codes for VFPCOM Utility

  Q192692 Rs2dbf.exe Converting ADO 2.x Recordset to VFP Cursor

(c) Microsoft Corporation 2000, All Rights Reserved. Contributions by Trevor
Hancock, Microsoft Corporation.


Additional query words: Vfpcom

======================================================================
Keywords          : kbCOMt kbDatabase kbOOP kbvfp300 kbvfp300b kbvfp500 kbvfp500a kbvfp600 KbDBFDBC kbGrpDSFox kbDSupport kbCodeSnippet 
Technology        : kbVFPsearch kbAudDeveloper kbVFP300 kbVFP300b kbVFP500 kbVFP600 kbVFP500a
Version           : WINDOWS:3.0,3.0b,5.0,5.0a,6.0
Issue type        : kbbug
Solution Type     : kbpending

=============================================================================

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