custom php forum - showing new/unread posts

Question

I have written myself a custom forum script using php. I decided against using phpbb and others as I wanted 100% flexibility with what I was doing.

I\'ve hit a problem

Answer 1

My approach would be to save the last post id of each topic a specific user has seen in the database:

user_id   topic_id   post_id
1         2          3

So, here you know that user 1 visited the third post in the second topic, but didn't look at the first topic at all.

To check if the user has new/unread topics you can first check for topic_id's which are not in this table for that user. To check if known topics have new messages you can compare the post_id with the last post_id of each topic. If they are not equal, there are new messages.