Hi all,
I'm a recent MySQL convert, and I am having some difficulty with
syntax on grouping a table by a foreign key and returning only the
newest entry that matches. In MySQL, you can do something like
event_log
------------
id
event_type
event_date
meaningful_data
SELECT
meaningful_data,
event_type,
event_date
FROM
event_log
GROUP BY
event_type
ORDER BY
event_date DESC
And this would return back the most recent event and meaningful data
for each event type. When I try this in postgres, I get errors about
either grouping by id or using id in an aggregate function. I am
afraid if I use it in an aggregate function, it will disrupt the sort
order I am attempting, and if I group by it, I no longer get the most
recent data for each event type, but I get every event. How would I
accomplish this is postresql? Is there some aggregate functions that
help with this, or should I be trying a different method altogether?
Grouping feels pretty different, and I suspect closer to standards, in
postgres. Unfortunately, my mind works (for the short term) in mysql.
Will someone please give me some pointers?
Thanks!
Corey
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