Here are some SQL statements I use to generate statistics about UDOIT usage.

udoit_statistics.sql

/* Count the number of scans run per day */
SELECT COUNT(1) AS scans, DATE(date_run) as date
FROM reports
GROUP BY DATE(date_run)

/* Count the number of scans run by each user */
SELECT user_id, COUNT(1) AS scans
FROM reports
GROUP BY user_id
ORDER BY scans DESC

/* List all courses, sorted by number of errors, descending */
SELECT course_id, file_path, MAX(errors)
FROM reports
GROUP BY course_id
ORDER BY MAX(errors) DESC

/* Count the number of scans per course for a given time range */
SELECT course_id, COUNT(1) AS scans
FROM reports
WHERE date_run BETWEEN CAST('2015-07-01' AS DATE) AND CAST('2016-06-30' AS DATE)
GROUP BY course_id
ORDER BY scans DESC

/* Count the number of new users per day */
SELECT COUNT(1) AS users, DATE(date_created) as date
FROM users
GROUP BY DATE(date_created)