Moving average - MySQL

Question

I'm trying to implement system-wide login throttling and I need to calculate the daily average number of failed login attempts from the last 3 months.

I'm currently inserting a record on every login fail, each with a timestamp. How can I do this in MySQL?

Thanks in advance for your help

Answer 1

SELECT AVG(cnt)
  FROM (SELECT COUNT(*) AS cnt
          FROM mytable
         WHERE `date` BETWEEN DATE_SUB(NOW(), INTERVAL 3 MONTH) AND NOW()
      GROUP BY DATE(`date`)) x

Assuming you have a table mytable with field date of type date, datetime or timestamp