Intelligent MySQL GROUP BY for Activity Streams

Question

I\'m building an activity stream for our site, and have made some decent headway with something that works pretty well.

It\'s powered by two tables:

Answer 1

Some observations about your desired results:

Some of the items are aggregated (Jack Sprat hearted seven sellers) and others are itemized (Lord Nelson chartered the Golden Hind). You probably need to have a UNION in your query that pulls together these two classes of items from two separate subqueries.

You use a fairly crude timestamp-nearness function to group your items ... DATE(). You may want to use more sophisticated and tweakable scheme... like this, maybe

  GROUP BY TIMESTAMPDIFF(HOUR,CURRENT_TIME(),stream_date) DIV hourchunk

This will let you group stuff by age chunks. For example if you use 48 for hourchunk you'll group stuff that's 0-48 hours ago together. As you add traffic and action to your system you may want to decrease the hourchunk value.