Update If Exists Else Insert - SQL

 Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        'jika stat_printer = 0 Or stat_cd1 = 0 Or stat_cd2 = 0 And stat_network = ON
        'maka kolom ttl_status = "ON"

        'Else

        'jika stat_printer = 1 Or stat_cd1 = 0 Or stat_cd2 = 0 And stat_network = ON
        'maka kolom ttl_status ="OFF"

        For Each x As DataGridViewRow In DataGridView1.Rows
            If Not x.IsNewRow Then
                If x.Cells("stat_printer").Value = 0 Or x.Cells("stat_cd1").Value = 0 Or
                    x.Cells("stat_cd2").Value = 0 AndAlso x.Cells("stat_network").Value = "ON" Then
                    x.Cells("ttl_status").Value = "ON"
                Else
                    x.Cells("ttl_status").Value = "OFF"
                End If
            End If
        Next

        Dim query, queryInsert As New System.Text.StringBuilder
        query.AppendLine("IF EXISTS (SELECT * FROM tbl_monitoring Where kd_store=@kd) ")
        query.Append("update tbl_monitoring Set")
        queryInsert.Append("Insert Into tbl_monitoring values(")

        For Each x As DataGridViewColumn In DataGridView1.Columns
            If Not x.Name = "kd_store" Then
                query.AppendFormat(" {0}=@p{1},", x.Name, x.Index)
                queryInsert.AppendFormat("@p{0},", x.Index)
            Else
                queryInsert.Append("@kd,")
            End If
        Next

        query.Length -= 1
        queryInsert.Length -= 1
        queryInsert.Append(")")
        query.AppendLine(" where kd_store = @kd ")
        query.AppendLine("Else ")
        query.Append(queryInsert.ToString)

        Using con As New SqlConnection("Server=.;Database=dummy;Trusted_Connection=True")
            Using cmd As New SqlCommand(query.ToString, con)
                Try
                    con.Open()
                    For Each x As DataGridViewRow In DataGridView1.Rows
                        If Not x.IsNewRow Then
                            cmd.Parameters.Clear()
                            For Each y As DataGridViewColumn In DataGridView1.Columns
                                If y.Name = "kd_store" Then
                                    cmd.Parameters.Add("@kd", SqlDbType.VarChar, 100).Value =
                                                                      x.Cells(y.Index).Value
                                Else
                                    cmd.Parameters.Add("@p" & y.Index, SqlDbType.VarChar, 100).Value =
                                                                   x.Cells(y.Index).Value
                                End If
                            Next
                            cmd.ExecuteNonQuery()
                        End If
                    Next
                    con.Close()
                    MsgBox("Done")
                Catch ex As Exception
                    MsgBox(ex.ToString)
                End Try
            End Using
        End Using

  End Sub