Re: Recursion and threaded message boards...

Hi Tony, Friday, August 10, 2007, 5:23:28 PM, you wrote: > I have to write some PHP backend code for a threaded message board. > The db has a message table, and each message has a parent id. > Does anyone have any advice for someone whos never done this in PHP? > I'm currently thinking that I write function that takes a db row as > an argument, and initially, it is passed the root node of the whole > tree. It is also probably passed a string variable. > The first thing it will do is append the code for itself to the string. > Then it will query the DB for all its children (with an order by post > timestamp), and for every child, it will call itself on that child row. > Am I on the right track? (I've done simmilar things in C++, just not in > PHP)... To be honest this is less of a PHP issue (at this stage) and more of a SQL one. What SQL package are you using? (MySQL? if so v4 or v5?). I would strongly consider looking at using a nested set system for the structure (or at least a derivative of it, there are many good ones out there) in combination with a standard parent/child hierarchy. You can wrap up nearly all of the complexity of this requirement (i.e. the tree walking / retrieval) on a stored procedure level with some decent table design. Cheers, Rich -- Zend Certified Engineer http://www.corephp.co.uk "Never trust a computer you can't throw out of a window"