Step 5: DataControl is made usable (RDS Tutorial)

Microsoft ActiveX Data Objects (ADO)

Step 5: DataControl is Made Usable (RDS Tutorial)

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  • Specify the program to be invoked on the server, and obtain a proxy.

  • Invoke the server program. Pass parameters to the server program that identifies the data source and the command to issue.

  • The server program obtains a Recordset object from the data source, typically by using ADO.

  • The server program returns the final Recordset object to the client application.

  • On the client, the Recordset object is optionally put into a form that can be easily used by visual controls.

  • Changes to the Recordset object are sent back to the server and used to update the data source.

Discussion

The returned Recordset object is available for use. You can examine, navigate, or edit it as you would any other Recordset. What you can do with the Recordset depends on your environment. Visual Basic and Visual C++ have visual controls that can use a Recordset directly, or indirectly, with the aid of an enabling data control.

For example, if you are displaying a Web page in Microsoft Internet Explorer, you might want to display the Recordset object data in a visual control. Visual controls on a Web page cannot access a Recordset object directly. However, they can access the Recordset object through the RDS.DataControl. The RDS.DataControl becomes usable by a visual control when its SourceRecordset property is set to the Recordset object.

The visual control object must have its DATASRC parameter set to the RDS.DataControl, and its DATAFLD property set to a Recordset object field (column).

In this tutorial, set the SourceRecordset property.

Sub RDSTutorial5()
   Dim DS as New RDS.DataSpace
   Dim RS as ADODB.Recordset
   Dim DC as New RDS.DataControl
   Dim DF as Object
   Set DF = DS.CreateObject("RDSServer.DataFactory", "http://yourServer")
   Set RS = DF.Query ("DSN=Pubs", "SELECT * FROM Authors")
   DC.SourceRecordset = RS            ' Visual controls can now bind to DC.
...

Next   Step 6: Changes are Sent to the Server