php/mysql special tree

I 开发者_高级运维was messing arround with code and i can't figure out to do this:

I have a Table in the database like this:

CREATE TABLE IF NOT EXISTS `nodetree` ( 
 `node` int(11) NOT NULL, 
 `prevnode` int(11) NOT NULL, 
 `nextnode` int(11) NOT NULL, 
 `nodename` varchar(30) NOT NULL, 
 `nodelink` varchar(255) NOT NULL, 
 PRIMARY KEY (`node`,`prevnode`, `nextnode`) 
) ENGINE=MyISAM DEFAULT CHARSET=utf8; 

What i want to do is to get php build that graph automatically with tables. Each node is a clickable link to node description.

Thanks in advance.

By definition a node in a tree can only have one parent. But that isn't the case in your example. What you really have here is a directed graph, not a tree. You might want to have a look at this link for a good example of how to represent and query a graph in SQL.