Question

Say I have a database table with three fields: id, content and timestamp.

Entries have been coming in all day, so there’s loads of entries and entries will still be coming in periodically.

When a visitor views my webpage that will display the entries, the page will display the 10 most recent PLUS any new entries that come in while the visitor is on the page.

I made a similar post about this issue, and the only answer I got was “USE LIMIT”, but I didn’t get a response if that would prohibit any new entries from coming in while the visitor is on the page.

Here’s what I’m getting at… I want to make the query to my database, then check each entry’s timestamp against a constant NOW() variable. I want to limit the amount the query goes back in time, but leave future posts open to infinity.

Answer 1

Bear with me if I am not completely answering you question. If I understand this correctly, the issue seems to be solved by doing two queries.

-- for the 10 most recent on page load
SELECT timestamp, content FROM table WHERE timestamp < NOW() LIMIT 10; 

Then store the latest item’s timestamp in a variable that I assume you can use in an AJAX call for stuff coming in “live” and use that timestamp to query future items.

SELECT timestamp, comment FROM table where timestamp > $last_timestamp LIMIT 10;

However, I would still limit the query number and continue to store w/e the last timestamp is in order to not hit an issue where a user sits on a page and the query results grow larger and larger as new posts are entered.