How records in the database are recursively added to the TREEVIEW__ database

Private Sub Startadd (TreeView TV)
 Dim s As String
 Dim root As Node

 ' Here you can first create a root node 
 set Root=tv.nodes.add ( ,, Key, "This is the root node")
 root.expand
 s= "Select *from tab where parentid= ' 0 '"
 ' for database query while
 (condition established)
  TV.NODES.AA (Root,tvchild,key,text)
  recurrencefun (tv,key)
  ' move to the next
 wend
End Sub

private Sub Recurrencefun (TreeView tv,node pnode,int Pid)
 Dim s As String 
 Dim node As Node

 s= "Select *from tab wher E parentid= ' + Pid + ' "
 ' for database query while
 (condition set)
  set Node=tv.nodes.aa (pnode,tvchild,key,text)
  Recurrencefun (TreeView tv,node,int Pid)
  ' moves to the next
 wend
End Sub