Populate Tree view in vb.net from data base(parent child realation)

Private Sub Filltree()
Dim DSNWind As DataSet


Dim oRead As System.IO.StreamReader
Dim EntireFile As String
oRead = IO.File.OpenText(Application.StartupPath() + "/connection.txt")
EntireFile = oRead.ReadToEnd()
'end soumen
Dim connectionString As String = EntireFile
Dim conn As New SqlConnection(connectionString)
Dim dadagdetails As New SqlDataAdapter("select dd.dagdeatilsid,'Land type--'+l.landtype+',Satak--'+cast(dd.quantity as varchar) as [Details]from tblDagdetails as dd inner join tbllandtype as l on dd.landtype=l.landtypeid where dd.dagid='" + cmbDag.SelectedValue.ToString() + "'", conn)
Dim daowner As New SqlDataAdapter("select * from tblowner ", conn)
Dim daownerrealation As New SqlDataAdapter("select * from tblOwner", conn)
DSNWind = New DataSet

dadagdetails.Fill(DSNWind, "dagdetails")
daowner.Fill(DSNWind, "owner")
daownerrealation.Fill(DSNWind, "ownerrealation")


'DSNWind = New DataSet()
' DSNWind = db.GetDataSet("select dd.dagdeatilsid,'Land type--'+l.landtype+',Satak--'+cast(dd.quantity as varchar) as [Details]from tblDagdetails as dd inner join tbllandtype as l on dd.landtype=l.landtypeid where dd.dagid='" + cmbDag.SelectedValue.ToString() + "'", "dagdetails")
' DSNWind = db.GetDataSet("select * from tblowner ", "owner") 'where dagdetailsid=
' DSNWind = db.GetDataSet("select * from tblOwner ", "ownerrealation") 'where


'Create a data relation object to facilitate the relationship between the Customers and Orders data tables.
DSNWind.Relations.Add("tblDagdetails", DSNWind.Tables("dagdetails").Columns("dagdeatilsid"), DSNWind.Tables("owner").Columns("dagdetailsid"))
DSNWind.Relations.Add("tblOwner", DSNWind.Tables("owner").Columns("ownerid"), DSNWind.Tables("ownerrealation").Columns("parentid"), False)
'''''''''''''''''''''''


TreeView1.Nodes.Clear()
Dim i, n As Integer
Dim parentrow As DataRow
Dim ParentTable As DataTable
ParentTable = DSNWind.Tables("dagdetails")

For Each parentrow In ParentTable.Rows
Dim parentnode As TreeNode
parentnode = New TreeNode(parentrow.Item(1))
TreeView1.Nodes.Add(parentnode)
''''populate child'''''
'''''''''''''''''''''''
Dim childrow As DataRow
Dim childnode As TreeNode
childnode = New TreeNode()
For Each childrow In parentrow.GetChildRows("tblDagdetails")
childnode = parentnode.Nodes.Add(childrow(3)) ' & " " & childrow(1) & " " & childrow(2))
childnode.Tag = childrow("dagdetailsid")
''''populate child2''''
''''''''''''''''''''''''''
Dim childrow2 As DataRow
Dim childnode2 As TreeNode
childnode2 = New TreeNode()
For Each childrow2 In childrow.GetChildRows("tblOwner")
childnode2 = childnode.Nodes.Add(childrow2(3))

Next childrow2
''''''''''''''''''''''''

Next childrow
'''''''''''''''
Next parentrow

End Sub