createLeftNode, createRightNode,createRootNode, createSubNode,deleteNode and moveTree. Not only 1 left, 1 right, 1 up and 1 down but also a part of a tree in a nother tree.
Well nested sets are great if you are working with hierarchical data. It's much more complex to implement it only with php arrays especially if you want to save these information in a database.
你可以试试这个.从未使用过，但经过简短的代码筛选后，它看起来几乎完成了.
you could try this on. Never used it but after a short code screening it looks almost complete.
