Get the hourly average amount based on rows with minutely timestamp - mysql

Question

I have a table structure that looks like this:
+---------+------------+----------+---------+-----------+------------+
| id | account_id | hashrate | workers | sharerate | timestamp |
+---------+------------+----------+---------+-----------+------------+
| 1227368 | 42 | 405211 | 1 | 6183 | 1534264380 |
| 1227367 | 12 | 450077 | 1 | 6868 | 1534264380 |
+---------+------------+----------+---------+-----------+------------+
A row is created every minute for a user with an active worker.
I'm attempting to display a chart that will show the average hashrate and sharerate for each hour over a 24 hour period.
My sql query so far is:
SELECT
timestamp,
SUM(hashrate) as hashes,
SUM(sharerate) AS shares
FROM statistics_users
WHERE FROM_UNIXTIME(timestamp) >= DATE_SUB(NOW(), INTERVAL 1 DAY)
GROUP BY timestamp;
which returns:
+------------+------------+----------+
| timestamp | hashes | shares |
+------------+------------+----------+
| 1534177980 | 2282744244 | 34831913 |
Which is returning 1440 objects (one for each minute of day). I want to group the items by hour and average all sums returned from my query of minutes into an hour. Not sure where to go from here and I'm fairly new to writing sql queries, so any help would be much appreciated.

Answer 1

We can use an expression that returns a representation of hour, basically trimming off minutes and seconds, and then GROUP BY that expression. One possibility it to use the MySQL DATE_FORMAT function.
SELECT DATE_FORMAT(FROM_UNIXTIME(t.timestamp),'%Y-%m-%d %H') AS ts_hr
, AVG(t.hashes)
, AVG(t.shares)
FROM (
-- original query goes here as inline view
SELECT timestamp
, SUM(hashrate) as hashes
, SUM(sharerate) AS shares
FROM statistics_users
WHERE FROM_UNIXTIME(timestamp) >= NOW() + INTERVAL -1 DAY
GROUP BY timestamp
) t
GROUP
BY DATE_FORMAT(FROM_UNIXTIME(t.timestamp),'%Y-%m-%d %H')
-- ^^^^^^^^^^^^ ^^^^^^^^^^^^^^^
Note that the condition in the WHERE clause doesn't respect hour boundaries, so we're going to get a partial result for first hour, and a partial last hour.
The specification isn't clear, as to whether we want the average of the sums for each timestamp, or more simply
SELECT DATE_FORMAT(FROM_UNIXTIME(t.timestamp),'%Y-%m-%d %H') AS ts_hr
, AVG(t.hashrate)
, AVG(t.sharerate)
FROM statistics_users t
WHERE FROM_UNIXTIME(t.timestamp) >= NOW() + INTERVAL -1 DAY
GROUP
BY DATE_FORMAT(FROM_UNIXTIME(t.timestamp),'%Y-%m-%d %H')
-- ^^^^^^^^^^^^ ^^^^^^^^^^^^^^^
https://dev.mysql.com/doc/refman/8.0/en/date-and-time-functions.html#function_date-format