Extracting future grades from SQL database

[Gwern Branwen]

So when I was doing my treadmill self-experiment writeup
(http://www.gwern.net/Treadmill#treadmill-effect-on-spaced-repetition-performance-randomized-experiment)
I had intended to analyze any effect of the treadmill usage on the
*next* review of flashcards reviewed then, but I couldn't figure out
the SQL query.

I recently got some help on that, and it turns out to be fairly
complex, so I'm posting it here as a guide for anyone else interested
in extracting information from Mnemosyne. You can get the grades, next
grades, timestamps, easiness and some other stuff with a query like
this:

SELECT timestamp,object_id,grade,easiness,thinking_time,actual_interval,(SELECT
grade FROM log AS log2 WHERE log2.object_id = log.object_id AND
log2.timestamp > log.timestamp ORDER BY log2.timestamp DESC LIMIT 1)
AS grade_future FROM log WHERE event_type==9;

(For those curious: no, the treadmill doesn't seem to affect later
reviews except as it influenced the present review negatively.)

--
gwern