Dim strConn, strSQL As String
strConn = "Provider=SQLOLEDB;Data Source=(local)\NetSDK;" & _
          "Initial Catalog=Northwind;Trusted_Connection=Yes;"
Dim cn As New OleDbConnection(strConn)
cn.Open()
strSQL = "SELECT CustomerID, CompanyName, ContactName FROM Customers"
Dim daCustomers As New OleDbDataAdapter(strSQL, cn)
strSQL = "SELECT OrderID, CustomerID, EmployeeID, OrderDate FROM Orders"
Dim daOrders As New OleDbDataAdapter(strSQL, cn)
 
Dim ds As New DataSet()
daCustomers.Fill(ds, "Customers")
daOrders.Fill(ds, "Orders")
cn.Close()
 
ds.Relations.Add("CustomersOrders", _
                     ds.Tables("Customers").Columns("CustomerID"), _
                     ds.Tables("Orders").Columns("CustomerID"))
 
Console.WriteLine("The parent DataTable now contains " & _
                  ds.Tables("Customers").Constraints.Count & _
                  " constraints")
Console.WriteLine("The child DataTable now contains " & _
                  ds.Tables("Orders").Constraints.Count & _
                  " constraints")