Enlazar 3 tablas con un Dataset

[univercity]

Gracias por leer!!
El problema que tengo es que necesito enlazar 3 tablas en un dataset o como sea, este es el codigo pero me queda grande alguien podría ayudarme.

Sub Page_Load(Sender As Object, E As EventArgs)

MyConnection = New OleDbConnection("PROVIDER=MICROSOFT.JET.OLEDB.4.0; DATA SOURCE=" & Server.MapPath("../****/vasijosas.mdb"))

If Not (IsPostBack)

Dim DS As DataSet
Dim MyCommand As OleDbDataAdapter

MyCommand = New OleDbDataAdapter("select distinct cosecha from inventario", MyConnection)
DS = new DataSet()
MyCommand.Fill(DS, "inventario")

MySelect.DataSource= DS.Tables("inventario").DefaultView
MySelect.DataBind()
End If
End Sub





Sub GetAuthors_Click(Sender As Object, E As EventArgs)

Dim SelectCmd As String = "select Cepa.inventario, Saldo.inventario, cosecha.inventario, fecha.comprobante, capacidad.cubas, bodega.cubas, cod_cuba.cubas, cuba.inventario from inventario, cubas, comprobante where cosecha.inventario = @Cosecha and cuba.inventario = cod_cuba.cubas "

Dim DS As DataSet
Dim MyCommand As OleDbDataAdapter

MyCommand = New OleDbDataAdapter(SelectCmd, MyConnection)

MyCommand.SelectCommand.Parameters.Add(New OleDbParameter("@cosecha", SqlDbType.NVarChar, 2))
MyCommand.SelectCommand.Parameters("@cosecha").Val ue = MySelect.Value

DS = new DataSet()
MyCommand.Fill(DS, "inventario")

MyDataGrid.DataSource= DS.Tables("inventario").DefaultView
MyDataGrid.DataBind()
End Sub


Gracias de Antemano!