Imports System.Data.SqlClient
 
Module Module1
 
    Sub Main()
        Dim rowvor As Integer
        Dim rownext As Integer
        Dim conn As SqlConnection
        conn = New SqlConnection("Server=UG04; Database=LABSQL;Integrated" & _
          "Security=true")
        conn.Open()
        Dim da As New SqlDataAdapter("SELECT * FROM [hlfKunde-Anlage]ORDER BY" & _
          "Kunde_ID", conn)
        Dim dt As New DataTable
        da.Fill(dt)
        Dim row As DataRow = dt.NewRow()
        dt.Columns.Add("Doublette")
        Dim n = 0
        Try
            For Each row In dt.Rows
                If dt.Rows(n).Item("Anlage_ID") Is DBNull.Value Then
                    dt.Rows(n).Item("Doublette") = 999999
                Else
                    rowvor = dt.Rows(n).Item("Anlage_ID")
                End If
                If dt.Rows(n + 1).Item("Anlage_ID") Is DBNull.Value Then
                    dt.Rows(n + 1).Item("Doublette") = 999999
                Else
                    rownext = dt.Rows(n + 1).Item("Anlage_ID")
                End If
                If rowvor = rownext Then
                    dt.Rows(n + 1).Item("Doublette") = 999999
                    Console.WriteLine("Datansatz zu löschen " & rownext)
                End If
                Console.WriteLine("Anlage: " & rownext)
                n = n + 1
            Next
        Catch ex As Exception
            Dim cb As SqlCommandBuilder
            cb = New SqlCommandBuilder(da)
            da.Update(dt)
            conn.Close()
        End Try
    End Sub
 
End Module