This article was previously published under Q253248
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This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.
Setting the Sort property of an ADO Recordset object whose CursorLocation property has not been explicitly set or has been set to adUseServer, causes the following error message to appear:
Runtime error '3251': The operation requested by the application is not supported by the Provider
Or, under MDAC 2.6 or later, the following message will appear:
Runtime error '3251': Current provider does not support the necessaryinterfaces for sorting or filtering.
The provider in use does not expose the OLEDB interfaces required by the ADO Sort method. These are optional interfaces. Most OLEDB providers do not support the Sort method when using server-side cursors.
The ADO Client Cursor Engine does support the Sort method. Set the CursorLocation property of the ADO recordset object to adUseClient before opening it.
If the OLEDB provider supports a query language, such as SQL, you can request the records in a sorted order. For example, the Microsoft Jet and Microsoft SQL Server OLEDB providers both support the SQL ORDER BY clause. If you want to re-sort the data, you have to either re-select it or use a client-side cursor.
This behavior is by design.
The default setting for the CursorLocation property of an ADO Recordset object when not specified explicitly is adUseServer. This setting uses a data provider or driver-supplied cursor to create the recordset.
Setting the CursorLocation property of the ADO recordset to adUseClient uses a client-side cursor supplied by the local cursor library to create and populate the recordset. The ADO Client Cursor Engine supports the Sort method and can be used if the OLDEB provider does not.
Steps to Reproduce Behavior
The following example uses the SQL Server 7.0 pubs database. The problem can also be reproduced using the Microsoft Jet OLEDB Provider and an Access database.
Open a new Standard EXE project in Visual Basic 5.0 or 6.0. Form1 is created by default.
On the Project menu, click References. Add a reference to the Microsoft ActiveX Data Objects Library.
Add a Command button (Command1) to the default form and change the Caption property to Sort Records.
Add the following code to the form:
Option ExplicitDim cn As ADODB.ConnectionDim rs As ADODB.RecordsetPrivate Sub Form_Load() Set cn = New ADODB.Connection cn.Open "Provider=SQLOLEDB.1;Data Source=MyServer;Initial Catalog=pubs;User ID=<user name>"End SubPrivate Sub Command1_Click() Set rs = New ADODB.Recordset' rs.CursorLocation = adUseClient rs.open "Select * from Authors", cn, adOpenKeyset, adLockReadOnly, adCmdText rs.Sort = "au_lname desc" Do While Not rs.EOF Debug.Print rs!au_lname rs.MoveNext Loop rs.CloseEnd Sub
Note You must adjust the connect string to point to a valid data source. Make sure that the User ID has the appropriate permissions to perform this operation on the database.
Run the project and click the Command button. Note that you see the error shown in the "Symptoms" section of this article.
Stop the project and uncomment the following line:
' rs.CursorLocation = adUseClient
Run the project again. Note that it completes successfully, and that the records print in descending order on au_lname.