threaded-comments

Let's say we have a table with user comments. First-level comments have a reference to an article they are attached to. Deeper-level comments do not have this reference by design but they have a reference to it's parent comment. For this database structure - what would be the most efficient way to fetch all comments for a given article and then render it in html format? (Let's assume that we have approx. 200 comments of first level and the deepiest level of 20) Bill Karwin I usually recommend a design called Closure Table . See example in my answer to What is the most efficient/elegant way to