主题：动态添加父节点和子节点

我可以在添加子节点的时候写SQL语句嘛？    如下代码好像有问题

Dim cmd As New SQLCommand
Dim dt As DataTable
Dim dr As DataRow
cmd.ConnectionName = ConnectDB

'增加根节点
Dim trroot As WinForm.TreeView
Dim nd As WinForm.TreeNode
trroot = e.Form.Controls("TreeView1")
nd = trroot.Nodes.Add("部门")
trroot.SelectedNode = nd
trroot.Select()
trroot.BeginEdit()

'增加子节点
Dim trchild As WinForm.TreeView
Dim nd1 As WinForm.TreeNode
Dim pardept As String
trchild = e.Form.Controls("TreeView1")
nd1 = trchild.SelectedNode
If nd1 IsNot Nothing Then
    cmd.CommandText = "select 部门简称 from 部门 "
    dt = cmd.ExecuteReader()
    dr = dt.DataRows(0)
    pardept = dr("部门简称")
    nd1 = nd1.Nodes.Add('" & pardept & "')
    trchild.SelectedNode = nd1
    trchild.Select
    trchild.BeginEdit
End If