关于treeview控件,求大佬指导

大概的方法
Dim conn As ADODB.Connection
    Dim rs As ADODB.Recordset
    Dim strSQL As String
    Dim rootNode As Node
    Dim symptomNode As Node
   
    ' 清空TreeView
    tvData.Nodes.Clear
   
    ' 建立数据库连接
    Set conn = New ADODB.Connection
    conn.ConnectionString = "Provider=SQLOLEDB;Data Source=ABC-PC;" & _
                           "Initial Catalog=.;User ID=用户名;Password=密码;"
    conn.Open
   
    ' 执行SQL查询
    strSQL = "SELECT 一级目录, 二级目录, 三级目录 FROM 根目录 ORDER BY 一级目录"
    Set rs = New ADODB.Recordset
    rs.Open strSQL, conn, adOpenStatic, adLockReadOnly
   
' 添加根节点
    Set rootNode = tvData.Nodes.Add(, , "root", "根目录名")
   
    ' 遍历记录集
    If Not rs.EOF Then
        rs.MoveFirst
        Do Until rs.EOF
            ' 添加脉证主节点
            Set symptomNode = tvData.Nodes.Add("root", tvwChild, "S" & rs.AbsolutePosition, _
                                              rs!一级目录(数据库字段))
            
            ' 添加药方子节点
            If Not IsNull(rs!二级目录(数据库字段)) Then
                tvData.Nodes.Add symptomNode.Key, tvwChild, "P" & rs.AbsolutePosition, _
                                "二级目录：" & rs!二级目录(数据库字段)
            End If
            
            ' 添加详细说明子节点
            If Not IsNull(rs!二级目录(数据库字段)) Then
                tvData.Nodes.Add symptomNode.Key, tvwChild, "p" & rs.AbsolutePosition, _
                                "二级目录：" & rs!二级目录(数据库字段)
            End If
            rs.MoveNext
        Loop