I have a problem updating a database from dataset. In particular adding a new row in the table of the the data set. It work in the data set but when i try to update the database with Update nothing happen, neither exception messages.
I think that the problem rises for the presence of a key column, but i don't know what to do!!!
Anyone can halp me?

Here is the code:

Imports System.Data
Imports System.Data.SqlClient
Imports System.Data.OleDb

Public Class Form1

Private Const CONNECTION_STRING2 As String = _
"Integrated Security=SSPI;Persist Security Info=False;" & _
"Initial Catalog=Northwind;Data Source=.\SQLEXPRESS"

Private Const CONNECTION_STRING As String = _
"Integrated Security=SSPI;Persist Security Info=False;" & _
"Initial Catalog=ITWORKS;Data Source=.\SQLEXPRESS"

Public conn As New SqlConnection(CONNECTION_STRING)
Public ConnNorth As New SqlConnection(CONNECTION_STRING2)
Public da As SqlDataAdapter
Public DaNorth As SqlDataAdapter

Public dataSet As DataSet = New DataSet
Public dataSet2 As DataSet = New DataSet
Public dataSet3 As DataSet = New DataSet

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
conn.Open()
da = New SqlDataAdapter()

Dim cmd As SqlCommand

Dim cmdtext As String
cmdtext = "SET IDENTITY_INSERT Employees ON; SELECT * FROM [ITWORKS].[dbo].[Employees]"
'cmdtext = " SELECT * FROM [ITWORKS].[dbo].[Employees]"

cmd = New SqlCommand(cmdtext, conn)
cmd.CommandType = CommandType.Text
cmd.Connection = conn

' Set the SqlDataAdapter's SelectCommand.
da.SelectCommand = cmd
'DataGrid1.DataSource = dataSet

dataSet = New DataSet()
dataSet.Clear()
da.Fill(dataSet)

dataSet.Tables(0).TableName = "Employees"
DataGrid1.DataSource = dataSet.Tables("Employees")
ConnNorth.Open()
DaNorth = New SqlDataAdapter()

Dim cmdNorthj As SqlCommand

cmdtext = "SET IDENTITY_INSERT Employees ON; SELECT * FROM [Northwind].[dbo].[Employees]"
cmdNorthj = New SqlCommand(cmdtext, ConnNorth)
cmdNorthj.CommandType = CommandType.Text
cmdNorthj.Connection = ConnNorth

' Set the SqlDataAdapter's SelectCommand.
DaNorth.SelectCommand = cmdNorthj

'dataSet = New DataSet("Employees")
DaNorth.Fill(dataSet2)
dataSet2.Tables(0).TableName = "EmployeesOriginale"

grdAll.DataSource = dataSet2.Tables("EmployeesOriginale")
conn.Close()
ConnNorth.Close()
'grdAll.DataSource = dataSet
'DataGrid1.Update()

End Sub

Private Sub DataGrid1_Navigate(ByVal sender As System.Object, ByVal ne As System.Windows.Forms.NavigateEventArgs) Handles grdAll.Navigate

End Sub

Private Sub btnUpdatate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdatate.Click

conn.Open()

Dim nuovaRow As DataRow
nuovaRow = dataSet2.Tables("EmployeesOriginale").Rows(0)
Console.WriteLine(nuovaRow(1))

Dim tSource As DataTable = dataSet.Tables("Employees")
DataGrid2.DataSource = tSource

dataSet.Tables("Employees").ImportRow(dataSet2.Tables("EmployeesOriginale").Rows(7))
dataSet.Tables("Employees").Rows(9).Item(0) = 10
DataGrid1.SetDataBinding(dataSet, "Employees")

Dim builder As SqlCommandBuilder = New SqlCommandBuilder(da)
Console.WriteLine(builder.GetUpdateCommand.CommandText)
builder.GetUpdateCommand()

da.Update(dataSet, "Employees")
conn.Close()
MsgBox("fatto")

End Sub
End Class