How do I implement threaded comments?

Question

I am developing a web application that can support threaded comments. I need the ability to rearrange the comments based on the number of votes received. (Identical to how threa

Answer 1

I'd add the following new fields to the above tabel:

• thread_id: identifier for all comments attached to a specific object

• date: the comment date (allows fetching the comments in order)

• rank: the comment rank (allows fetching the comment order by ranking)

Using these fields you'll be able to:

1. fetch all comments in a thread in a single op
2. order comments in a thread either by date or rank

Unfortunately if you want to preserve your queries DB close to SQL standard you'll have to recreate the tree in memory. Some DBs are offering special queries for hierarchical data (f.e. Oracle)

./alex