I have the following columns in a table: posts.id posts.parentId REFERENCES posts.id
This represents a tree that has a single root node, and each node can have 0 or more children. posts.id is the id number of a node, and posts.parentId is the id number of that node's parent (is NULL for the root node). Is there a way to do "SELECT ... FROM posts ORDER BY <magic>" where <magic> is something that will give me depth-first-traversal order? The best solution I've been able to think of so far, short of reading the entire tree into memory and sorting it with a procedural language such as Perl, is to make a new column called "posts.order" and do "ORDER BY posts.order", and have some code that maintains posts.order whenever a new node is inserted into the tree. I was hoping there's a way MySQL could automatically keep track of depth-first-traversal order for me, though... -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
