vb.net datatable Serialize to json

Question

I have this kind of table:

I need to get this JSON (of course order could be any, structure/tree

Answer 1

The 'Oh-no you didn't' version:

Public Function GetJson(ByVal dt As DataTable) As String
    Return New JavaScriptSerializer().Serialize(From dr As DataRow In dt.Rows Select dt.Columns.Cast(Of DataColumn)().ToDictionary(Function(col) col.ColumnName, Function(col) dr(col)))
End Function

Answer 2

Here is my solution:

Public Function GetJson() As String

    Dim dt As New System.Data.DataTable
    dt = CreateDataTable() 'here I retrive data from oracle DB
    Dim serializer As New System.Web.Script.Serialization.JavaScriptSerializer()
    Dim packet As New List(Of Dictionary(Of String, Object))()
    Dim row As Dictionary(Of String, Object) = Nothing

    Try
        Dim result() As DataRow = dt.Select("Parent_ = 'main'")
        Dim i As Integer
        For i = 0 To result.GetUpperBound(0)
            row = New Dictionary(Of String, Object)()
            If UCase(result(i)(2)) <> "HAS CHILD" Then
                row.Add(result(i)(0), result(i)(2))
            Else
                row.Add(result(i)(0), add_(dt, result(i)(0)))
            End If
            packet.Add(row)
        Next i

        Return serializer.Serialize(packet)
    Catch ex As Exception
        MsgBox(ex.ToString)
        Me.Close()
    End Try

End Function

Public Function add_(ByVal dt As System.Data.DataTable, ByVal parent_ As String) As Dictionary(Of String, Object)
    Dim row As Dictionary(Of String, Object) = Nothing
    Try
        Dim result() As DataRow = dt.Select("Parent_ = '" & parent_ & "'")
        Dim i As Integer
        row = New Dictionary(Of String, Object)()
        For i = 0 To result.GetUpperBound(0)

            If UCase(result(i)(2)) <> "HAS CHILD" Then
                row.Add(result(i)(0), result(i)(2))
            Else
                row.Add(result(i)(0), add_(dt, result(i)(0)))
            End If
        Next i
    Catch ex As Exception
        MsgBox(ex.ToString)
    End Try
    Return row
End Function