Q189852: HOWTO: Change Databindings on the Fly

Article: Q189852
Product(s): Microsoft Visual Basic for Windows
Version(s): 
Operating System(s): 
Keyword(s): kbGrpDSVBDB
Last Modified: 09-JAN-2000

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

- Microsoft Visual Basic Enterprise Edition for Windows, version 6.0 
-------------------------------------------------------------------------------

SUMMARY
=======

Changing data bindings for a textbox requires changing the DataSource and the
the DataField. Set the DataField property of the textbox to Empty prior to
resetting the DataSource and the DataField. If this is not done you will
encounter the following error.

  "Run time Error 545
  Unable to bind to field DataMember: 'fieldname'"

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

Step-by-Step Example
--------------------

1. Create a standard.exe project. Form1 is created by default. Check the
  following under project references:

     Microsoft ActiveX Data Objects 2.0 Library
     Microsoft Data Binding Collection

2. Place a Textbox and a CommandButton on the form.

3. Paste the following code in the code window for the form:

        Dim rsProducts As ADODB.Recordset
        Dim rsCustomers As ADODB.Recordset

        Private Sub Command1_Click()

          If Text1.DataField = "CompanyName" Then
            Text1.DataField = Empty
            Set Text1.DataSource = rsProducts
            Text1.DataField = "ProductName"
          Else
            Text1.DataField = Empty
            Set Text1.DataSource = rsCustomers
            Text1.DataField = "CompanyName"
          End If

        End Sub

        Private Sub Form_Load()
         'set up recordsets
         Set rsProducts = New ADODB.Recordset
         Set rsCustomers = New ADODB.Recordset
         rsProducts.Open "Select * from Products", _
                       "Provider=Microsoft.Jet.OLEDB.3.51; " & _
                       "Data Source=c:\school\nwind.mdb", _
                       adOpenstatic, adLockOptimistic
         rsCustomers.Open "Select * from Customers", _
                       "Provider=Microsoft.Jet.OLEDB.3.51; " & _
                       "Data Source=c:\school\nwind.mdb", _
                       adOpenstatic, adLockOptimistic

         Set Text1.DataSource = rsCustomers
         Text1.DataField = "CompanyName"

        End Sub

4. Run the form and press the CommandButton repeatedly. It will alternate the
  contents of the textbox between companyname and Productname. Alter the 'Data
  Source' in the Open statement above to fit your environment.

REFERENCES
==========

In the MSDN, select Visual Basic Documentation, and query on "data binding"

Additional query words: databinding kbbetapublic kbDSupport kbdse kbVBp kbvbp600

======================================================================
Keywords          : kbGrpDSVBDB 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVB600
Issue type        : kbhowto

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

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1986-2002.