Updating datatable/datagridview to a DIFFERENT/existing table

Private Sub Load(...) Handles Button1.Click
   Dim dataAdapter As New OleDb.OleDbDataAdapter(sqlStr1, connStr)
   dataAdapter.Fill(dt)
   DataGridView1.DataSource = dt
End Sub 

Private Sub Move(...) Handles Button2.Click
   dt1 = dt.Copy
   DataGridView2.DataSource = dt1
End Sub 

Private Sub Update(...) Handles Button3.Click
   Dim dataAdapter As New OleDb.OleDbDataAdapter(sqlStr2, connStr)
   Dim commandbuilder As New OleDb.OleDbCommandBuilder(dataAdapter)
   dataAdapter.Update(dt1)
End Sub