Grafana with MySQL exponential growth graph - mysql

Question

I have a MySQL table to record the number of users
id
email
name
created
1
user1#example.com
John
2019-02-05 18:53:50.000000
2
user2#example.com
Rock
2019-02-06 18:53:50.000000
3
user3#example.com
Sena
2019-02-08 18:53:50.000000
4
user4#example.com
Anny
2019-02-08 18:53:50.000000
I want to get the exponential growth in count per day
date
count
2019-02-05
1
2019-02-06
2
2019-02-07
2
2019-02-08
4
And draw a similar graph on the Grafana portal
I tried using count() but it gives the count of data per day
The query generated on Graphana is
SELECT
UNIX_TIMESTAMP(created) DIV 86400 * 86400 AS "time",
count(id) AS "Verified"
FROM custom_domain_customdomain
WHERE
is_cname_verified = '1' AND
is_txt_verified = '1'
GROUP BY 1
ORDER BY UNIX_TIMESTAMP(created) DIV 86400 * 86400

Answer 1

Here is an example of the steps to create your cumulative count based on a contiguous date range.
The date_range CTE is based on one of the RECURSIVE CTE examples in the MySQL docs
The second CTE is a fairly straightforward LEFT JOIN from the date_range to your users table to do the count of new users per day.
The final SELECT query uses SUM() as a window function to give the cumulative user count.
WITH RECURSIVE
`date_range` (`date`) AS (
-- retrieve minimum date from users for start of date_range
SELECT DATE(MIN(`users`.`created`)) FROM `users`
UNION ALL
SELECT `date` + INTERVAL 1 DAY
FROM `date_range`
-- retrieve maximum date from users for end of date_range
WHERE `date` + INTERVAL 1 DAY <= (SELECT DATE(MAX(`users`.`created`)) FROM `users`)
),
`users_per_day` AS (
SELECT
`date_range`.`date` AS `created_date`,
COUNT(`users`.`id`) AS `new_user_count`
FROM `date_range`
LEFT JOIN `users` ON `users`.`created` BETWEEN `date_range`.`date` AND (`date_range`.`date` + INTERVAL 1 DAY - INTERVAL 1 SECOND)
GROUP BY `date_range`.`date`
)
SELECT
`created_date`,
`new_user_count`,
SUM(`new_user_count`) OVER (ORDER BY `created_date`) as `cumulative_count`
FROM `users_per_day`;
The users_per_day CTE and final SELECT can be combined but I have left them separate as it clearly shows the steps used and the overhead is negligible.