CODEWITHSUNDEEP
mysql
Anuj Gakhar
Anuj Gakhar

Reputation: 691

mysql query (fetch number of users based on their activity)

I have 2 MySQL tables (user and comments) - what I want to do is fetch a report that gives me how many users made 1 comment, how many users made 2 comments, how many users made 3 comments and how many users made 4+ comments, grouped by month and year.

I have this query to get the number of comments made by each user grouped by year/month

select year(c.datecreated) as comment_year, month(c.datecreated) as comment_month,      
count(c.id) as num_comments
from tblcomments c
inner join tbluser u on u.id = c.userid
where 
c.datecreated <= '2013-02-19' and c.datecreated >= '2012-03-01'
group by c.userid, year(c.datecreated), month(c.datecreated)

How do I modify this query to give me the results I want?

Upvotes: 1

Views: 81

Answers (2)

sgeddes
sgeddes

Reputation: 62861

Here is one way to do it -- not sure you need to join on the tbluser, but I left it there:

SELECT comment_year, comment_month,
  COUNT(userId) userCnt,
  Num_Comments 
FROM (
  select 
    year(c.datecreated) as comment_year, 
    month(c.datecreated) as comment_month,      
    c.userid,
    CASE WHEN count(c.id) >= 4 THEN '4+' ELSE CAST(COUNT(c.id) as varchar) END as num_comments
  from tblcomments c
    inner join tbluser u on u.id = c.userid
  where 
    c.datecreated <= '2013-02-19' and c.datecreated >= '2012-03-01'
  group by c.userid, year(c.datecreated), month(c.datecreated)
  ) t
GROUP BY comment_year, comment_month, Num_Comments;

And some sample fiddle: http://sqlfiddle.com/#!3/5fb5c/5

Upvotes: 0

eggyal
eggyal

Reputation: 126025

Use a subquery to group your results a second time:

SELECT   ym, 
         SUM(c = 1) AS `num_1`,
         SUM(c = 2) AS `num_2`,
         SUM(c = 3) AS `num_3`,
         SUM(c>= 4) AS `num_4+`
FROM (
  SELECT   DATE_FORMAT(datecreated, '%Y-%m') AS ym, COUNT(*) AS c
  FROM     tblcomments
  WHERE    datecreated BETWEEN '2012-03-01' AND '2013-02-19'
  GROUP BY ym, userid
) t
GROUP BY ym

Upvotes: 2

Related Questions