how i can get these with mysql? - mysql

Question

I am new to mysql.
I have on survey with clicks, period(date). Now i have to find out number of clicks per month, like:
MON CLICKS
nov 0
oct 34
sep 67
aug 89
I have used code like this:
select MONTHNAME(period) mon, IFNULL(count(id),0) as Clicks
from survey
where period > DATE_SUB(now(), INTERVAL 3 MONTH)
group by EXTRACT(MONTH FROM period)
It is not working for with no records.
Here one thing I suppose there is no record in that month it should show 0: if there is no record in nov the number of clicks should be 0.
my table structure was like this
CREATE TABLE `survey` (
`id` int(2) NOT NULL auto_increment,
`period` datetime default NULL)
for last four weeks i have used
SELECT uq.timespan, COALESCE(tsq.TotalClicks, 0) as Clicks FROM (
SELECT '22-28 days' as timespan
union SELECT '15-21 days'
union SELECT '8-14 days'
union SELECT 'up to 7 days'
)uq LEFT JOIN (
SELECT CASE
WHEN submitdate >= NOW() - INTERVAL 4 WEEK
AND submitdate < NOW() - INTERVAL 3 WEEK THEN '22-28 days'
WHEN submitdate >= NOW() - INTERVAL 3 WEEK
AND submitdate < NOW() - INTERVAL 2 WEEK THEN '15-21 days'
WHEN submitdate >= NOW() - INTERVAL 2 WEEK
AND submitdate < NOW() - INTERVAL 1 WEEK THEN '8-14 days'
WHEN submitdate >= NOW() - INTERVAL 1 WEEK THEN 'up to 7 days'
END Weeksubmitdate,
count(id) TotalClicks
FROM survey
WHERE submitdate >= NOW() - INTERVAL 4 WEEK
GROUP BY Weeksubmitdate
)tsq ON uq.timespan = tsq.Weeksubmitdate
Any help?

Answer 1

I usually do Pivot table to achieve this. Assuming your click information is stored into a table named SURVEY and assuming only the date/time of the click is stored into one column of the SURVEY table (which is all what you need) then here is one way to do it:
select year(period),
sum(case when month(period)=1 then 1 else 0 end) jan,
sum(case when month(period)=2 then 1 else 0 end) feb,
sum(case when month(period)=3 then 1 else 0 end) mar,
sum(case when month(period)=4 then 1 else 0 end) apr,
sum(case when month(period)=5 then 1 else 0 end) may,
sum(case when month(period)=6 then 1 else 0 end) jun,
sum(case when month(period)=7 then 1 else 0 end) jul,
sum(case when month(period)=8 then 1 else 0 end) aug,
sum(case when month(period)=9 then 1 else 0 end) sep,
sum(case when month(period)=10 then 1 else 0 end) oct,
sum(case when month(period)=11 then 1 else 0 end) nov,
sum(case when month(period)=11 then 1 else 0 end) dec
from survey
group by year(period)
The output is something like:
---------------------------------------------------------------------------------
| Year | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC |
---------------------------------------------------------------------------------
| 2012 | 5 | 20 | 13 | 0 | 0 | 65 | 15 | 0 | 0 | 21 | 0 | 0 |
---------------------------------------------------------------------------------
I even set up the same Fiddle SQL for you
SQL Fiddle Demo
An alternative way (Column based for the last 4 months even with ZERO count):
SQL Fiddle Demo
SELECT mon,
sum(clicks) clicks
FROM ( SELECT month(period) mnth,
date_format(period,'%b') mon,
count(1) clicks
FROM survey
WHERE month(period) BETWEEN month(curdate()) - 4 AND month(curdate())
GROUP BY 1, 2
UNION ALL
SELECT 1 mnth, 'Jan' mon, 0 clicks
UNION ALL
SELECT 2 mnth, 'Feb' mon, 0 clicks
UNION ALL
SELECT 3 mnth, 'Mar' mon, 0 clicks
UNION ALL
SELECT 4 mnth, 'Apr' mon, 0 clicks
UNION ALL
SELECT 5 mnth, 'May' mon, 0 clicks
UNION ALL
SELECT 6 mnth, 'Jun' mon, 0 clicks
UNION ALL
SELECT 7 mnth, 'Jul' mon, 0 clicks
UNION ALL
SELECT 8 mnth, 'Aug' mon, 0 clicks
UNION ALL
SELECT 9 mnth, 'Sep' mon, 0 clicks
UNION ALL
SELECT 10 mnth, 'Oct' mon, 0 clicks
UNION ALL
SELECT 11 mnth, 'Nov' mon, 0 clicks
UNION ALL
SELECT 12 mnth, 'Dec' mon, 0 clicks) a
WHERE mnth BETWEEN month(curdate()) - 4 AND month(curdate())
GROUP BY 1
ORDER BY mnth

Answer 2

You need to join to a table that contains all month names. Here's one way to do it:
select
mon,
ifnull(count(id), 0) as Clicks
from (select 'nov' as mon union select 'oct' union select 'sep' union select 'aug') m
left join survey on MONTHNAME(period) = mon
where submitdate > DATE_SUB(now(), INTERVAL 3 MONTH)
group by 1

Answer 3

select MONTHNAME(STR_TO_DATE(month(period), '%m'))as 'month',count(*) as clicks
from survey group by month(period)