I want to develop a forum where all data is stocked on my mysql database. What I want to know is if threads in my forum will be accessible via search engine like google (Considering the fact that all data from each thread will be stock on my database) .... If not, what is the best way to develop a forum if I want data to be accessible via search engine. .. thanks.
As long as there are links to the forum posts in your page, the googlebot will crawl them. For example the googlebot hits webdeveloper.com, follows all the links it finds, and indexes the pages. If you have some mystery linking going on, then it would cause problems, otherwise you will be fine.