将邻接列表模型和嵌套集模型结合起来是否被认为是糟糕的设计？
我正在努力在 MySQL 中构建树结构，并一直在尝试不同的表示数据的方式。但无论怎么切，都存在不足之处。
嵌套集模型允许我轻松选择树的整个分支 - 这是我需要做的。然而，选择节点的直接子节点并不那么容易。
邻接列表模型非常适合获取直接子节点，但不太适合返回树的整个分支。
我想知道，构建这样的树结构有什么特别不好的地方吗：
TABLE: Tree
ID
name
lft
rgt
parentID
所以我所拥有的是邻接列表模型和嵌套集模型都在同一个表中。这样我就可以使用 / 或，具体取决于我选择的情况。
人们的想法是什么？这是允许的吗？ （花生酱和巧克力终于在一起了？）或者这被认为是糟糕的设计？
提前致谢，
I'm working on building a tree structure in MySQL and have been experimenting with different ways of representing the data. However, no matter how I slice it, there are shortcomings.
The nested sets model allows me to easily select entire branches of the tree - which I need to do. However it is not so easy to select immediate children of a node.
The adjacency list model is great for getting immediate children, but not so good for returning entire branches of the tree.
I'm wondering, is there anything particularly bad about building a tree structure like this:
TABLE: Tree
ID
name
lft
rgt
parentID
So what I have is the adjacency list model and the nested sets model all in the same table. That way I can use either / or, depending on the circumstances of what I am selecting for.
What are peoples' thoughts? Is this allowed? (Peanut butter and chocolate together at last?) Or is this considered bad design?
Thanks in advance,
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我本人强烈推荐它。这是 CakePHP 用于其树结构的样式，正如您所指出的，它为您提供了很大的灵活性。您只需要做更多的工作来确保树的完整性，但这是非常值得的。
I highly recommend it myself. This is the style which CakePHP uses for its tree structures, and as you pointed out, it gives you great flexibility. You just need to do a bit more work to ensure the integrity of your tree, but it's quite worth it.
不，它的设计一点也不差。至少在我看来。
然而我只会实现一个。例如，我使用邻接列表模型作为添加新元素和检索的主要方法。（显然是检索，因为它很容易）但是，我还为嵌套集添加了parentId。
这样做的好处是，我可以随时重建我的 ALM，并且可以轻松地快速移动内容，前提是我保留了parentId。
但是，我不会在您的代码中使用两者，只是将其放在后台...
编辑评论
您提到选择直接子项并不那么容易。我想你可能做错了什么。即使在邻接列表中选择直接子项也非常容易。
如果您创建一个新问题，我将回答如何做到这一点。
No, its not bad design at all. At least in my opinion.
I would however only implement one. For example, I used Adjacency List Model as my prime method of adding new elements and retreiving.. (obviously retreiving since its so easy) however, I also added parentIds for Nested Set.
The benefit of this is that I can rebuild my ALM at any time and can easily move things quickly providing I keep the parentIds.
I would not use both in your code however, just have it there in the background...
Edited Comments
You mention that it is not so easy to select immediate children. I think you might be doing something wrong. It is extremely easy even in Adjacency List to select the immediate children.
If you create a new question I will answer how to do it in that.