Difference between revisions of "Working with OleDB"

Revision as of 06:48, 18 January 2022

Note that since Lianja 6.3 you can integrate Lianja and VFP with concurrent data access.

See blog article:

https://www.lianja.com/community/entry.php?14-HOWTO-integrate-Lianja-and-VFP-with-concurrent-data-access

You can use OleDB with the VFP OleDB driver if you need to work directly with existing VFP data. This works in desktop and cloud Apps.

OleDB is a COM technology so it is Windows-only. As opposed to ODBC, which is platform independent; Windows, Linux and macOS.

There is an updated version of the VFP OleDB Provider from the one included in Visual FoxPro 9.0 It is available for download from:
http://microsoft.com/downloads/details.aspx?FamilyId=E1A87D8F-2D58-491F-A0FA-95A3289C5FD4&displaylang=en%7Chere

An ODBC driver for VFP can be downloaded from https://www.devart.com/odbc/

private oConn, oRS, m_count
oConn = createobject("ADODB.Connection")
oRS = createobject("ADODB.Recordset")
lcConnString = "Provider=vfpoledb;Data Source=C:\Temp\Northwind\northwind.dbc"
oconn.ConnectionString = lcConnString
oconn.Open()
oRS.Open("select * from customers where customerid='BOTTM'", oconn)
m_count = oRs.fields.count
// display the first record selected
for i=0 to m_count
    try
        ? "Name=" + oRS.Fields.item(i).Name + ",value=" + etos(oRS.Fields.item(i).Value)
    catch
        // ignore error from Memo
    endtry
endfor

Notice how you must use the item() method on the Fields property as this is exposed only as a property not a method.

The output produced is as follows:

Name=customerid,value=BOTTM
Name=companyname,value=Bottom-Dollar Markets                   
Name=contactname,value=Elizabeth Lincoln             
Name=contacttitle,value=Accounting Manager            
Name=address,value=23 Tsawassen Blvd.                                          
Name=city,value=Tsawassen      
Name=region,value=BC             
Name=postalcode,value=T2F 8M4   
Name=country,value=Canada         
Name=phone,value=(604) 555-4729          
Name=fax,value=(604) 555-3745  

Note: There is a known issue with retrieving memo fields using the VFP OleDB driver which is why TRY/CATCH to ignore the error.