从查询填充多维数组(递归关系)

Question

我正在尝试填充一个支持以下递归关系的多维数组（DATA来自数据库表）。

这个多维数组将用于生成下面的列表。我在VB.NET中使用多维数组的经验很少。如果有任何帮助，我将不胜感激。如果你认为有更好的方法来实现这一点，请告诉我。

数据

ID      NAME                PARENTID
10      Bobby Brown         50          
20      Dave Matthew        80
30      Sergey Boostad      50
40      Linda View          50
50      Bill Lumberg        
60      Rina Gina           50
70      Ben Thompson        100
80      Maria Tree          50
90      Gustav Duffield     80
100     Jon Theodore        
110     Cedric Loomis       100 
120     Jeremy Oscar        100

输出（实现）

[50] - Bill Lumberg
    [10] - Bobby Brown
    [30] - Sergey Boostad
    [40] - Linda View
    [60] - Rina Gina
    [80] - Maria Tree
        [20] - Dave Matthew
        [90] - Gustav Duffield
[100] - Jon Theodore    
    [70] - Ben Thompson
    [110] - Cedric Loomis       
    [120] - Jeremy Oscar

Answer 1

要在内存中存储树，可以创建一个类，如下所示：

Public Class NameNode
    Public Sub New(name As String)
        Me.Name = name
    End Sub
    Public Property Name As String
    Public Level As Integer
    Public Property Children As New List(Of NameNode)
End Class

然后，你可以这样使用它：

Dim bill As New NameNode("Bill Lumberg")
bill.Children.Add(New NameNode("Bobby Brown")
bill.Children.Add(New NameNode("Sergey Boostad")

要从平面DataSet填充它，您需要制作一个递归方法，例如：

Public Function BuildNode(data As DataSet, nameId As Integer, level As Integer), As NameNode
    Dim node As New NameNode()
    node.Level = level
    ' Find name with the ID in the dataset and set the node's name property accordingly
    Dim childIds As New List(Of Integer)
    ' Search Get a list of all the name ID's that have the current ID as their parent
    For Each i As Integer In childIds
        node.Children.Add(BuildNode(data, i, level + 1))
    Next
    Return node
End Function

然后你可以通过这样称呼它来建立整个Bill Lumberg分支机构：

Dim bill As NameNode = BuildNode(data, 50, 0)