用于目录结构的数据结构？ [英] Data structure used for directory structure?

问题描述

我正在制作一个用户构建目录的程序（不在Windows中，在我的应用程序中），在这些文件夹中有子文件夹等等;每个文件夹都必须包含文件夹或文档。什么是最好的数据结构使用？请注意，用户可以选择子文件夹并搜索其中的文档及其子文件夹。我不想限制文件夹或子文件夹级别。

解决方案

这就是我所做的：

数据库中的每个记录都有两个字段：ID和ParentID。 ID为4-5个字符（Base36，a-z：0-9或类似的东西）。父ID是父级完整结构的连接...

所以...

此结构：

 根
文件夹1 
文件夹2 
文件夹3 
文件夹4 
文件夹5 
文件夹6 
  

将如下所示：

  ID ParentID名称
 
 0000 NULL ROOT 
 0001 0000 Folder1 
 0002 0000 Folder2 
 0003 00000002 Folder3 
 0004 0000 Folder4 
 0005 00000004 Folder5 
 0006 000000040005 Folder6 
  

I像这样的结构，因为如果我需要找到一个文件夹下的所有文件，我可以做一个查询，如：

  SELECT * FROM文件夹WHERE ParentID LIKE'0000％' - 查找Folder1下的所有文件夹
  

要删除文件夹和所有其孩子：

  DELETE FROM文件夹WHERE ID ='0004'和ParentID LIKE'00000004％'
  

移动文件夹及其子，您必须将所有使用相同父级的记录更新为新的父级。

而且我不想使用文件夹或子文件夹级别

对此的明显限制是子文件夹的数量限制为您的ParentID字段的大小。 / p>

I'm making a program which the user build directories (not in windows, in my app) and in these folders there are subfolders and so on; every folder must contain either folders or documents. What is the best data structure to use? Notice that the user may select a subfolder and search for documents in it and in its subfolders. And I don't want to limit the folders or the subfolders levels.

解决方案

This is what I do:

Every record in the database has two fields: ID and ParentID. IDs are 4-5 characters (Base36, a-z:0-9 or something similar). Parent IDs are a concatenation of the parent's complete structure...

So...

This structure:

Root
   Folder1
   Folder2
      Folder3
   Folder4
      Folder5
         Folder6

Would be represented like this:

ID     ParentID     Name

0000   NULL           ROOT
0001   0000           Folder1
0002   0000           Folder2
0003   00000002       Folder3
0004   0000           Folder4
0005   00000004       Folder5
0006   000000040005   Folder6

I like this structure because if I need to find all the files under a folder I can do a query like:

SELECT * FROM Folders WHERE ParentID LIKE '0000%' -- to find all folders under Folder1

To delete a folder and all its children:

DELETE FROM Folders WHERE ID='0004' AND ParentID LIKE '00000004%'

To move a folder and its children, you have to update all the records that use the same parent, to the new parent.

And I don't want to linit the folders or the subfolders levels

An obvious limitation to this is that the number of subfolders are limited to the size of your ParentID field.

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