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

GROUP BY YEAR(record_date), MONTH(record_date)

Check out the date and time functions in MySQL.

Answer 2

I prefer to optimize the one year group selection like so:

SELECT COUNT(*)
  FROM stats
 WHERE record_date >= :year 
   AND record_date <  :year + INTERVAL 1 YEAR;

This way you can just bind the year in once, e.g. '2009', with a named parameter and don't need to worry about adding '-01-01' or passing in '2010' separately.

Also, as presumably we are just counting rows and id is never NULL, I prefer COUNT(*) to COUNT(id).

Answer 3

.... group by to_char(date, 'YYYY') --> 1989

.... group by to_char(date,'MM') -->05

.... group by to_char(date,'DD') --->23

.... group by to_char(date,'MON') --->MAY

.... group by to_char(date,'YY') --->89

Answer 4

If you want to group by date in MySQL then use the code below:

 SELECT COUNT(id)
 FROM stats
 GROUP BY DAYOFMONTH(record_date)

Hope this saves some time for the ones who are going to find this thread.

Answer 5

Complete and simple solution with similarly performing yet shorter and more flexible alternative currently active:

SELECT COUNT(*) FROM stats
-- GROUP BY YEAR(record_date), MONTH(record_date), DAYOFMONTH(record_date)
GROUP BY DATE_FORMAT(record_date, '%Y-%m-%d')

Answer 6

I tried using the 'WHERE' statement above, I thought its correct since nobody corrected it but I was wrong; after some searches I found out that this is the right formula for the WHERE statement so the code becomes like this:

SELECT COUNT(id)  
FROM stats  
WHERE YEAR(record_date) = 2009  
GROUP BY MONTH(record_date)