Contents of Visual FoxPro 1.0 ODBC Vfpodbc.txt File

Last reviewed: October 14, 1997
Article ID: Q150149

1.00 WINDOWS kbinterop kbreadme

The information in this article applies to:

Microsoft Visual FoxPro ODBC Driver version 1.0

SUMMARY

Below is Microsoft Visual FoxPro Open Database Connectivity (ODBC) 1.0 Vfpodbc.txt file, located in the Windows System subdirectory.

MORE INFORMATION

Microsoft Visual FoxPro ODBC Driver Version 1.0 ReadMe File

This document provides late-breaking or other information that supplements the Microsoft Visual FoxPro ODBC Driver Help file.

How to Use This Document

To view the ReadMe file in Windows Notepad, maximize the Notepad window and click Word Wrap on the Edit menu. To print the ReadMe file, open it in Notepad or another word processor, and then use the Print command on the File menu.

INSTALLATION NOTES

     1.1  System Requirements
     1.2  Installing from Disk
     1.3  Adding a Data Source
     1.4  Information Resources

DISK CONTENTS

     2.1  Files on Disk
     2.2  Files Installed By SETUP.EXE

TROUBLESHOOTING

     3.1  Installation Problems
     3.2  Unsupported Commands in Existing Stored Procedures
     3.3  ODBC Troubleshooting Tools
     3.4  Contacting Product Support Services

ADDITIONAL INFORMATION

     4.1  Data Files That Can Be Accessed by the Driver
     4.2  Driver Capabilities
     4.3  Driver Limitations
     4.4  Default Environment Settings
     4.5  Default Column Names For Expressions
     4.6  Known Issues With SQL Server Replication and Office Applications

ADDITIONAL EXAMPLES

     5.1  Accessing Visual FoxPro Data from Microsoft Excel
     5.2  Accessing Visual FoxPro Data from Visual Basic

1. INSTALLATION NOTES

     1.1  System Requirements
     1.2  Installing from Disk
     1.3  Adding a Data Source
     1.4  Information Resources

1.1 System Requirements

To install the Visual FoxPro ODBC Driver, you need:

 * Windows NT 3.50 (or later) or Windows 95
 * 2 MB disk space

Important: Visual FoxPro ODBC Driver 1.0 is a 32-bit driver only. Windows 3.1 and Windows for Workgroups platforms are not supported.

1.2 Installing from Disk

1 Place the Visual FoxPro ODBC Driver installation disk into the A: drive. 2 On Windows 95, choose Run from the Start button.

  -or-
  On Windows NT, choose Run from the Program Manager File menu.

3 Type "A:\SETUP.EXE" without quotes and press ENTER.

NOTE: The Visual FoxPro ODBC Driver installation updates the ODBC components to ODBC 2.5 compliance if necessary. See the README25.TXT file in your Windows system directory for additional information on enhancements or features of the ODBC 2.5 components.

1.3 Adding a Data Source

In order to use any ODBC driver from an ODBC-aware application, you must first set up a data source. For instructions on adding a data source, search for "Adding a Visual FoxPro data source" in Help.

1.4 Information Resources

The following information is available to help you:

 * Help files
 * ReadMe files
 * Microsoft Press Books
 * MSDN

Help Files

The Visual FoxPro ODBC Driver comes with two help files, located in your Windows system directory:

 * ODBCINST.HLP  General ODBC information
 * DRVVFP.HLP  The Visual FoxPro ODBC Driver Help file

ReadMe Files

The Visual FoxPro ODBC Driver comes with two readme files, located in your Windows system directory:

 * VFPODBC.TXT  This file.
 * README25.TXT  Contains information specific to ODBC 2.5 components

Microsoft Press Books

Microsoft publishes two books on ODBC:

 * Microsoft ODBC 2.0 Programmer's Reference and SDK Guide
   (ISBN#: 1-55615-658-8).
 * Inside ODBC (ISBN#: 1-55615-815-7).

Check your local book store for third party books on ODBC or newly released MS Press books on ODBC.

MSDN

See MSDN for ODBC revision information on versions 2.1 through 2.5.

2. DISK CONTENTS

     2.1  Files on Disk
     2.2  Files Installed By SETUP.EXE

2.1 Files on Disk

EXTRACT.EXE SETUP.EXE SETUP.INI SETUP.LST SETUP.TDF VFPODBC.INF VFPODBC.TXT VFPODBC1.CAB

2.2 Files Installed By SETUP.EXE

CTL3D32.DLL             Dialog DLL.
DRVVFP.HLP              The Visual FoxPro ODBC Driver help file; the

primary resource for information on the driver.

FOXPRO.INT              Collation support for some Eastern European

languages.

VFPODBC.DLL             The Visual FoxPro ODBC Driver.
VFPODBC.TXT             This file, containing additional information on the

Visual FoxPro ODBC Driver.

README25.TXT            ReadMe file for the ODBC 2.5 component changes.

3. TROUBLESHOOTING

     3.1  Installation Problems
     3.2  Unsupported Commands in Existing Stored Procedures
     3.3  ODBC Troubleshooting Tools
     3.4  Contacting Product Support Services

3.1 Installation Problems

>>>To troubleshoot installation problems 1 Clean-boot the machine. For example, under Windows 95, start in Safe Mode. 2 Make sure that nothing else is running, including virus software, Terminate and Stay Resident (TSR) applications, third party shells, or toolbars such as Microsoft Office Manager. 3 If the computer has video or system ROM shadowing, clear these options before reinstalling. 4 Scan the installation disks for damage and request new disks if they are damaged. 5 Re-install the driver.

3.2 Unsupported Commands in Existing Stored Procedures

The Microsoft Visual FoxPro ODBC Driver supports only a subset of the commands and functions available in the Visual FoxPro language. If a trigger contains an unsupported command or function, the Visual FoxPro ODBC Driver will return a "Trigger Failed" error message and ignore the INSERT, UPDATE, or DELETE command associated with the trigger.

Trigger code can be customized to execute code conditionally, depending on

whether the code is being executed by the driver or by Visual FoxPro.   You

can use the following template to create conditional code:

IF VERSION() = "Visual FoxPro ODBC Driver"

   * [Insert trigger code that is supported by the Visual FoxPro ODBC

Driver] ELSE

   * [Insert trigger code supported by Visual FoxPro]

ENDIF

See the Help file, DRVVFP.HLP, for a list of supported and unsupported commands and functions.

3.3 ODBC Troubleshooting Tools

You can troubleshoot ODBC problems with ODBC Test and ODBC Spy applications, available in the Microsoft ODBC SDK. You can use the 32-bit version of ODBC Spy to determine the ODBC function and parameters that caused the problem to occur. You can then use the 32-bit version of ODBC Test to verify the cause of the problem by submitting specific function calls with the parameters you identified. For additional information on using these utilities, refer to the ODBC 2.0 Programmer's Reference and SDK guide in Chapter 4: Using ODBC Test, and Chapter 5: Using ODBC Spy.

Note:   Only the 32-bit version of ODBC Spy and ODBC Test can be used

because the Visual FoxPro ODBC Driver is fully 32-bit.

An ODBC Trace Log can be generated by using the 32-bit version of ODBC Spy or by using the ODBC 32-bit Administrator.

>>>To generate an ODBC trace log: 1 In the Control Panel, double-click the 32bit ODBC icon. 2 In the Data Sources dialog box, click Options. 3 Select Trace ODBC Calls and Stop Tracing Automatically. 4 Click Select File and provide a log file name. 5 Click Save. 6 Click OK. 7 Click Close.

Now when you execute your code, all C ODBC API calls, their input parameters, and their output will be written to the log file. The ODBC log file is ASCII text and may be viewed in any standard ASCII text editor such as Microsoft Word, Notepad, or WordPad.

3.4 Contacting Product Support Services

If you have a question that requires technical support, prepare the following information before you call:

* The version numbers of any Microsoft products you are using * The type of hardware that you are using * The exact wording of any messages that appeared on your screen * A description of what happened and what you were doing when the problem occurred * A description of how you tried to solve the problem * Any ODBC Trace logs

When you call, be at your machine and have the Visual FoxPro ODBC Help file and any other related product documentation available, and then call one of the following numbers:

* If you are a registered user of Visual FoxPro, call (425) 635-7191, and have your product identification number available.

* If you have successfully installed the driver but are having trouble using it with your ODBC-aware application, contact the support provider for your application.

* If you do not own Visual FoxPro, you can call (900) 555-2300 or (800) 936- 5800 and use the Microsoft Technical Support "Pay As You Go" options.

* If you have issues with the ODBC API or other advanced issues, call the Advanced Systems "Pay As You Go" support line at (800) 936-5900.

4. ADDITIONAL INFORMATION

     4.1  Data Files That Can Be Accessed by the Driver
     4.2  Driver Capabilities
     4.3  Driver Limitations
     4.4  Default Environment Settings
     4.5  Default Column Names For Expressions
     4.6  Known Issues With SQL Server Replication and Office Applications

4.1 Data Files That Can Be Accessed by the Driver

The driver supports FoxBase+ and FoxPro tables as well as dBASE IV tables.

FoxBase+ and FoxPro Tables

The Visual FoxPro ODBC Driver gives you access to FoxBase+, FoxPro 1.x, FoxPro 2.x and Visual FoxPro 3.0 tables. The Visual FoxPro ODBC Driver also provides access to tables that are associated with a Visual FoxPro database container (DBC).

Note: The Visual FoxPro ODBC Driver allows transactions only on tables within a Visual FoxPro database. You cannot create transactions on free tables.

dBASE IV Tables

The Visual FoxPro ODBC Driver gives you access to dBASE IV and earlier tables. The dBASE files are supported in the following manner: * dBASE v2.x and 3.x: The files are read without conversion. * dBASE v4.x and 5.x: If the files do not have memo fields and the table has fewer than 255 columns, the files are read. * dBASE v4.x and 5.x tables with memo fields or dBASE indexes: These files require conversion in Visual FoxPro for Windows before they can be used with the Visual FoxPro ODBC Driver. The driver will not read or convert files. If you attempt to connect to a dBASE file that contains a memo field or index, an error will occur.

4.2 Driver Capabilities

International Support

You can set the collating sequence for index ordering. For a list of supported collating sequences, search for SET COLLATE in Help.

The default collating sequence is "MACHINE".   The collating sequence can

be changed by: * Selecting a different collating sequence from the driver options in the Data Source Setup dialog box. * Setting SET COLLATE TO cSequenceName with the ODBC function SQLExecDirect(). * Calling SQLPrepare() and SQLExecute() (see the ODBC 2.0 Programmer's Reference and SDK Guide).

Note: Support for the Eastern European code pages depends on the FOXPRO.INT file, which is installed by the Visual FoxPro ODBC Driver in your Windows system directory. If it is removed, the collating sequences on Eastern European code page machines will not work.

Remote Views and Parameterized Views

Any time the SQLTables() function is called, remote and parameterized views are excluded from the list. Local views based on parameterized views are not excluded, but will generate errors if you use them. If you call the SQLTables() function with a unique table name, however, you will find views if they are present, so that you can check for name conflicts.

4.3 Driver Limitations

You must use Visual FoxPro, not the Visual FoxPro ODBC Driver, to:

   * Use remote views. Remote views are not supported in the driver.
   * Update local views. Changes to views from the driver affect only the

view cursors, not the base tables.

   * Update base tables.
   * Call stored procedures directly. Using the driver, stored procedures

can only be called from a rule or trigger.

   * Create some index types. The driver can create only Primary or Unique

indexes, using the ALTER TABLE command. The driver cannot create an index on a free table.

   * Create transactions on free tables.  The Visual FoxPro ODBC Driver

allows transactions only on tables within a database, not on free tables.

   * Remove records marked for deletion. The PACK command is not supported

by the driver.

   * Convert dBASE files that have indexes or memo fields.

4.4 Default Environment Settings The default settings for the following SET commands are different from their default settings in Visual FoxPro.

Environment/SET command    Driver's Default Value
-----------------------    ----------------------
EXCLUSIVE                  OFF
NULL                       ON
DELETED                    ON
ANSI                       ON

4.5 Default Column Names For Expressions

The Visual FoxPro ODBC Driver names columns based on expressions using a combination of the expression operator and expression field. For example, the driver returns min_customerid as the name of the expression field in the result set for the following statement:

   SELECT MIN (customer_id) FROM customers

If you want to control the expression field name, use the AS clause. The following example returns 'minimum_custid' as the name of the expression field:

   SELECT MIN(customer_id) AS minimum_custid FROM customers

4.6 Known Issues With SQL Server Replication and Office Applications

SQL Server Replication

* When creating a character field, note that the Visual FoxPro maximum character field length is 254 characters, while the SQL Server maximum character field length is 255 characters.

* In order for replication to work properly, do not export indexes.

MSQuery Issues

To access a Visual FoxPro data source from a Microsoft Office application, you must have the MSQuery add-in; however, MSQuery is not installed by default with Microsoft Office applications. You can install MSQuery by reinstalling Excel or another Office component, choosing the Custom installation option, and then selecting the MSQuery add-in.

Using MSQuery To Create Visual FoxPro Tables When creating a table with MSQuery, the Type box in the Table Definition dialog box displays the following characters: B,C,D,F,G,I,L,M,M NOCPTRANS, N,T, and Y. For topics containing a definition of these data types, search for "field data types" in Help. The table describing data types is displayed when you click on the green 'data type' link.

Note: It is not possible to create a table that includes a Visual FoxPro Character Binary data type with MSQuery.

Invalid Field Names and MSQuery

MSQuery allows you to create invalid Visual FoxPro field names in tables. For example, "1995sales" is not a valid field name in Visual FoxPro, but MSQuery allows you to create it. When you open the table, you will get an error.

5. ADDITIONAL EXAMPLES

     5.1  Accessing Visual FoxPro Data from Microsoft Excel
     5.2  Accessing Visual FoxPro Data from Visual Basic

5.1 Accessing Visual FoxPro Data from Microsoft Excel

>>>To use Visual Basic for Applications in Excel to access Visual FoxPro data: 1 Start Microsoft Excel. 2 From the Insert menu, choose Macro and then Module. 3 Type the following code into the blank Macro editing window:

Sub MainRoutine()
    Dim Id As Variant
    Dim Constring As String   ' The connect string
    Dim Sql         ' The SQL Select command string
    Dim rc As Variant      ' The return code from a function
    Dim re As Variant      ' The returned error code from SQLError

    ' Initialize variables
    Constring =

"DSN=testdata;DBQ=c:\vfp\samples\data\testdata.dbc;FIL=FoxPro 3.0"

    Sql = "SELECT * from employee"

    ' Connect to the data source
    Id = SQLOpen(Constring)

    ' Execute the select command to return data
    rc = SQLExecQuery(Id, Sql)

    ' If there is an error, display it and exit
    If IsError(rc) Then
        re = SQLError()
        MsgBox "SQL Error. Error Message:" & re(3)
        Exit Sub
    End If

    ' Retrieve the data and put it into worksheet Sheet1
    rc = SQLRetrieve(Id, Worksheets("Sheet1").Range("A1"))

    ' Close the connection
    SQLClose Id
End Sub

4 From the Tools menu, choose References. 5 Select the XLODBC.XLA check box and click OK. Note: If XLODBC.XLA does not exist in the list, select Browse and find XLODBC.XLA in the Microsoft Excel Library\MsQuery directory. 6 From the Run menu, choose Start. 7 Click the Sheet1 tab to display the data.

5.2 Accessing Visual FoxPro Data from Visual Basic

>>>To access Visual FoxPro data with a Visual Basic Remote Data Object (RDO): 1 Define a data source named TasTradeDSN that connects to TASTRADE.DBC. 2 Start the Enterprise Edition of Visual Basic and create a form. 3 From the Tools menu, choose Custom Controls. 4 In the Available Tools list, select Microsoft Remote Data Control. 5 From the object toolbar, drop an RDO control on the form and set these properties:

   DataSourceName:   TastradeDSN (This example requires a data source named

TastradeDSN that connects to TASTRADE.DBC.)

   Connect:   ODBC=TastradeDSN
   CursorDriver:   0-ODBC Cursor if needed
   SQL:      select * from customer
   ResultType:   3-Static
   LockType:   1-ReadOnly

6 Drop a text box on the form and set these properties:

   DataSource:   MSRDC1 (the RDO control)
   DataField:   company_name

7 Drop a command button on the form and set these properties:

   Caption:   Skip 1

8 Add the following code to the command button's Click event:

   MSRDC1.Resultset.MoveNext

9 Run the form and click the Skip 1 command button.

Additional reference words: 1.00 VFoxWin 3.00 3.00b readme.txt
KBCategory: kbinterop kbreadme
KBSubcategory: FxinteropOdbc
Keywords : FxinteropOdbc kbinterop kbreadme
Version : 1.00
Platform : WINDOWS

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Last reviewed: October 14, 1997
© 1998 Microsoft Corporation. All rights reserved. Terms of Use.