Using ADO to Pass Recordset Objects to the Middle Tier

You can use the ADOR.Recordset object to marshal recordsets from a client Web page to a middle-tier business object. For example, suppose a user connects to a virtual shopping mall and selects a number of items to purchase. The selected items appear in the virtual shopping cart that is implemented with the RDS.DataControl object and buffered in a rowset. When the client clicks the purchase button, an ADOR.Recordset object is created and passed to an application server as an input parameter to a business function (ApplyUpdates). This causes the Recordset to be marshaled across to the server. The ApplyUpdates business function then connects to the Sales database and applies the updates.

' Code on a client Web page.
Sub PurchaseItem_OnClick
   Set rst = ADC1.Recordset

' The following option tells the recordset to only send 
' back changed records when updating. This makes the roundtrips 
' more lightweight. 
   rst.MarshalOptions = adMarshalModifiedOnly

' Call the ApplyUpdates function on the MyObj
' business object and pass the ador.Recordset
' object as an input parameter.
   MyObj.ApplyUpdates rst

End Sub


' VB code in the business object.
' ApplyUpdates is a method in a 
' middle-tier business object. 
Sub ApplyUpdates(rst As ADOR.Recordset)

   rst.ActiveConnection =  _
      "DSN=SalesDB;UID=SMgr;PWD=password"

' Save the changed records. 
   rst.UpdateBatch

End Sub