I’m trying to create a normalized database for a blog allowing reply to comments. Given a few answers I found, it seems that I need to look at the adjacency list model and the modified preorder tree traversal algorithm. However, after reading a bit about it, I haven’t found an example of it using foreign keys to enforce data integrity. Can it be done?
What database design do you recommend in this case? Ideally, I’d like to be able to eliminate a parent comment, and by using PK-FK relationships (PK = primary key, FK = foreign key) also be able to eliminate all the child comments in order to avoid keeping orphans in the table.
UPDATE: As a clarification, I’d also like to know which database design is used in blogs that allow reply to comments (that is, comments that reply to a comment that reply to an original thread).
Reddits source code is open source on Github, see how they do it….