MySQL Query GROUP BY day / month / year

Question

Is it possible to make a simple query to count how many records I have in a determined period of time like a year, month, or day, having a TIMESTAMP field, like

Answer 1

If you want to get a monthly statistics with row counts per month of each year ordered by latest month, then try this:

SELECT count(id),
      YEAR(record_date),
      MONTH(record_date) 
FROM `table` 
GROUP BY YEAR(record_date),
        MONTH(record_date) 
ORDER BY YEAR(record_date) DESC,
        MONTH(record_date) DESC

Answer 2

Here's one more approach. This uses [MySQL's LAST_DAY() function][1] to map each timestamp to its month. It also is capable of filtering by year with an efficient range-scan if there's an index on record_date.

  SELECT LAST_DAY(record_date) month_ending, COUNT(*) record_count
    FROM stats
   WHERE record_date >= '2000-01-01'
     AND record_date <  '2000-01-01' + INTERVAL 1 YEAR
   GROUP BY LAST_DAY(record_date) 

If you want your results by day, use DATE(record_date) instead.

If you want your results by calendar quarter, use YEAR(record_date), QUARTER(record_date).

Here's a writeup. https://www.plumislandmedia.net/mysql/sql-reporting-time-intervals/ [1]: https://dev.mysql.com/doc/refman/8.0/en/date-and-time-functions.html#function_last-day