HOWTO: Do SQL Server 7.0 Distributed Queries With FoxPro .dbf Files

• Microsoft FoxPro for Windows, versions 2.6, 2.6a
• Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0, 5.0a, 6.0
• Microsoft SQL Server version 7.0

SUMMARY

This article demonstrates how to perform a SQL Server distributed query to retrieve data from FoxPro .dbc and .dbf files.

MORE INFORMATION

Microsoft SQL Server version 7.0 provides the ability to perform queries against OLE DB providers. This is done by using the OpenQuery or OpenRowset Transact-SQL functions or by using a query with four-part names including a linked-server name.

For example:

sp_addlinkedserver 'mylinkedserver', 'product_name', 'myoledbprovider', 'data_source','location', 'provider_string', 'catalog'

SELECT * FROM OPENQUERY(mylinkedserver, 'select * from table1')

You should use the Microsoft OLE DB provider for ODBC (MSDASQL) and the Visual FoxPro ODBC driver to set up a linked server to perform distributed queries against FoxPro .dbc and .dbf files. Using Jet OLEDB Provider with FoxPro is not supported.

The following T-SQL code example demonstrates how to set up and use distributed queries with FoxPro with OpenQuery and OpenRowset functions. It also demonstrates how to update a remote FoxPro table from SQL Server 7.0. You can test this code in SQL Query Analyzer after you install the Visual FoxPro ODBC driver on a SQL Server 7.0 machine. You will need to change the data source names and path to FoxPro files as appropriate:

/* OPENROWSET and OPENQUERY examples with VFP via ODBC OLE DB provider */ 

/* These OPENROWSET examples depend on the sample files VFP98\data\Testdata.dbc
Modify your code accordingly for differences in location or DBC name */ 

--====================================================
-- Using DBC file , read and update
--====================================================
-- OPENROWSET DSN-less example

select * from openrowset('MSDASQL',
'Driver=Microsoft Visual FoxPro Driver;
SourceDB=e:\VFP98\data\Testdata.dbc;
SourceType=DBC',
'select * from customer where country != "USA" order by country')
go

select * from  openrowset('MSDASQL',
'Driver=Microsoft Visual FoxPro Driver;
SourceDB=e:\VFP98\data\Testdata.dbc;
SourceType=DBC',
'select * from customer where region="WA"')
go

Update  openrowset('MSDASQL',
'Driver=Microsoft Visual FoxPro Driver;
SourceDB=e:\VFP98\data\Testdata.dbc;
SourceType=DBC',
'select * from customer where region="WA"')
set region = "Seattle" 
go

-- check to verify which rows were updated
select * from  openrowset('MSDASQL',
'Driver=Microsoft Visual FoxPro Driver;
SourceDB=e:\VFP98\data\Testdata.dbc;
SourceType=DBC',
'select * from customer where region="Seattle"') 
go

-- OPENROWSET DSN example
/* Note the DSN Example might fail if SQL Server is configured to use a local account.*/ 
select * from openrowset('MSDASQL',
'DSN=Visual FoxPro Database;
SourceDB=e:\VFP98\data\Testdata.dbc;
SourceType=DBC',
'select * from customer where country != "USA" order by country')
go

/* sp_addlinkedserver examples */ 
-- sp_addlinkedserver example with DSN

/* You will need to make a DSN and point it to the Testdata database. 
Modify your code accordingly for differences in location or DBC name */ 

/* Note this Example may fail if SQL Server is configured to use a local account.*/ 
sp_addlinkedserver 'VFP Testdata Database With DSN', 
    '', 
    'MSDASQL',
    'VFP System DSN'
go

sp_addlinkedsrvlogin 'VFP Testdata Database With DSN', FALSE, NULL, NULL, NULL
go 

SELECT *
FROM OPENQUERY([VFP Testdata Database With DSN], 'select * from customer where region = "Seattle" ') 
go

-- Update using OpenQuery
Update OPENQUERY([VFP Testdata Database With DSN], 'select * from customer where region="WA"') 
set region = "Seattle" 
go

/* SP_addlinkedserver example with DSN-less connection */ 

/* This example also depends on the sample files Testdata.dbc
Modify your code accordingly for differences in location or DBC name */ 

sp_addlinkedserver 'VFP Testdata Database With No DSN', 
    '', 
    'MSDASQL',
    NULL,
    NULL,
'Driver={Microsoft Visual FoxPro Driver};UID=;PWD=;SourceDB=e:\VFP98\data\Testdata.dbc;SourceType=DBC;Exclusive=No;BackgroundFetch=Yes;Collate=Machine;'
go

sp_addlinkedsrvlogin 'VFP Testdata Database With No DSN', FALSE, NULL, NULL, NULL
go

SELECT *
FROM OPENQUERY([VFP Testdata Database With No DSN], 'select * from customer where country != "USA" order by country') 
go

--====================================================
-- Using VFP 6.0 driver, read and update data from VFP sample dbf files
--====================================================

-- OPENROWSET DSN-less example

select * from openrowset('MSDASQL',
'Driver=Microsoft Visual FoxPro Driver;
SourceDB=e:\VFP98\data;
SourceType=DBF',
'select * from customer where country != "USA" order by country')
go

-- perform UPDATE

Update openrowset('MSDASQL',
'Driver=Microsoft Visual FoxPro Driver;
SourceDB=e:\VFP98\data;
SourceType=DBF',
'select * from customer where region="Seattle"')
set region = "WA" 
go

-- verify update

select * from openrowset('MSDASQL',
'Driver=Microsoft Visual FoxPro Driver;
SourceDB=e:\VFP98\data;
SourceType=DBF',
'select * from customer where region = "WA"')
go<BR/>

-- OPENROWSET DSN example
-- DSN points to the folder where .dbf files are.
/* Note this Example may fail if SQL Server is configured to use a local account.*/ 
select * from openrowset('MSDASQL',
'DSN=Visual FoxPro Tables;			
SourceDB=e:\VFP98\data;
SourceType=DBF',
'select * from customer where country != "USA" order by country') 
go 

REFERENCES

For more details on setting up and using Distributed Queries, take a look at sp_addlinkedserver, OpenQuery, OpenRowset and related topics in SQL 7.0 Books Online.

To learn more about FoxPro, and .dbf and .dbc files, refer to the FoxPro product documentation.

Additional query words:

Keywords : kbDatabase kbOLEDB kbSQLServ kbVC kbVFp300b kbVFp500 kbVFp500a kbVFp600 kbGrpFox
Version : WINDOWS:2.6,2.6a,3.0,3.0b,5.0,5.0a,6.0; winnt:7.0
Platform : WINDOWS winnt
Issue type : kbhowto