How To Create a Recordset from a Variant Array with RDS

MORE INFORMATION

The following code creates a Visual Basic ActiveX DLL that contains two methods. One method generates the recordset and the other method updates the recordset.

The client program that is created in Visual Basic tests the functionality of the component.

You can also use the RDS.Datacontrol to create a recordset from a variant array.

Step-by-Step Example

1. Start Visual Basic and create a business object (ActiveX DLL) project. Name the ActiveX DLL Project RDSRecordset.
2. Rename the default class name (class1) to MyClass.
3. Add a project reference to the Microsoft Remote Data Services Server Library and the Microsoft ActiveX Data Objects Library.
4. Paste the following code into the Declarations section of the class:

         Dim ADF As New RDSServer.DataFactory
         Dim rs As New ADODB.Recordset
         Public Function GetRS() As Variant
   
         Dim ColInfo(1), c0(3), c1(3)
   
         c0(0) = "Name"          ' Column name.
         c0(1) = CInt(129)       ' Column type (129 = adChar).
         c0(2) = CInt(40)        ' Column size.
         c0(3) = False           ' Is the column nullable?
   
         c1(0) = "Age"           ' Column name.
         c1(1) = CInt(3)         ' Column type (3 = adInteger).
         c1(2) = CInt(-1)        ' Column size.
         c1(3) = True            ' Is the column nullable?
   
         ' Add the columns to the recordset definition.
         ColInfo(0) = c0
         ColInfo(1) = c1
   
         ' Actual creation of Recordset from the variant array.
   
         Set rs = ADF.CreateRecordSet(ColInfo)
         rs.AddNew
         rs(0) = "Tom"
         rs(1) = 20
         rs.Update
         rs.AddNew
         rs(0) = "anotherTom"
         rs(1) = 21
         rs.Update
         Set GetRS = rs
   
         End Function
   
         Public Function ProcessRs(rs As Variant) As Variant
   
          ' Add another row to the recordset and send it back to the client.
          rs.AddNew
          rs(0) = "YetanotherTom"
          rs(1) = 30
          rs.Update
          Set ProcessRs = rs
   
         End Function
   					

5. Compile and create the RDSRecordset.dll file.
6. Create the Visual Basic client application, RDSRecordsetClient. Create a Standard .exe project.
7. Add a reference to the RDSRecordset.dll file and to the Microsoft ActiveX Data Objects Library.
8. Place the following objects on the default form:

   Object            Name          Caption
         =========================================================
   
         List box          lstFields
         Command button    cmdGetRs      Get data.
         Command button    cmdUpdate     Update data.
         Command button    cmdSendData   Send data.
         Command button    cmdEnd        E&xit
         Form              frmMain       Creating recordsets without
                                         connecting to a database.
   					

9. Paste the following code into the General Declarations of the frmMain form:

          Dim myObj As New RDSRecordset.myClass
          Dim myrs As New ADODB.Recordset
   
          Private Sub cmdGetRS_Click()
   
            ' Call the method of our object to get the recordset.
            Set myrs = myObj.GetRS
   
            DisplayData
            cmdGetRS.Enabled = False
            cmdUpdate.Enabled = True
   
         End Sub
   
         Private Sub cmdSendData_Click()
   
            'Call another method on your object to update the recordset
            ' and return it back.
            Set myrs = myObj.ProcessRs(myrs)
         DisplayData
         ReInitializeCmd
   
         End Sub
   
         Private Sub cmdUpdate_Click()
   
         ' Update the local recordset.
           cmdSendData.Enabled = True
           myrs.MoveFirst
           myrs.Fields(0).Value = "Changed1"
           myrs.Update
           DisplayData
           cmdUpdate.Enabled = False
   
         End Sub
   
         Private Sub Form_Load()
   
           Set myrs = myObj.GetRS
           ReInitializeCmd
   
         End Sub
   
         Private Sub DisplayData()
   
           myrs.MoveFirst
           lstFields.Clear
           Do While Not myrs.EOF
              lstFields.AddItem myrs.Fields(0).Value
              myrs.MoveNext
           Loop
   
         End Sub
   
         Public Sub ReInitializeCmd()
   
            cmdSendData.Enabled = False
            cmdUpdate.Enabled = False
            cmdGetRS.Enabled = True
   
         End Sub
   
         Private Sub cmdEnd_Click()
   
           Set myObj = Nothing
           Set myrs = Nothing
           End
   
         End Sub
   					

10. Run the client program.