MySQL Count Including 0 - mysql

Question

I'm trying to get a total count of entries by month, over the course of several months. Here is the query I'm using:
SELECT COUNT(siteCount) AS Hits, DATE_FORMAT(TIMESTAMP,'%b') AS Month
FROM count
WHERE redirectDomain LIKE 'http://domain.com'
AND DATE_FORMAT(TIMESTAMP,'%Y') = '2013'
AND DATE_FORMAT(TIMESTAMP,'%b') BETWEEN 'Sep' AND 'Nov'
GROUP BY DATE_FORMAT(TIMESTAMP,'%b')
This is working great except when the count is 0. The month of Nov has 0 entries so it does not show in the results. How can I get Nov included in the results and showing a count of 0?
I'm guessing I need either ISNULL or CASE, but I've tried both and cannot figure out how to make this work.
Thanks for the help.

Answer 1

You're correct, it's not returning your month field because there aren't any rows (which is why your count is zero) - you could replace your count with a subselect which will keep them seperate from grouping etc:
SELECT
(SELECT
COUNT(c2.siteCount)
FROM
count c2
WHERE
redirectDomain
LIKE
'http://domain.com'
AND c2.TIMESTAMP = c1.TIMESTAMP) as Hits,
DATE_FORMAT(TIMESTAMP, '%b') AS Month,
FROM count c1
-- ...
I have a feeling you shouldn't be using TIMESTAMP either... reserved words...?

Answer 2

I have solved your problem,just follow this-
I created a table..
create table test(month text,site_count int null);
insert into test values('Sept',1),('Oct',1);
insert into test(month) values('Nov');
I did not give any value in the site_count column for the month 'Nov' i.e. the site_count of 'Nov' is null.Now I tried to count the site_count column according to the months and tried to get '0' for the month 'Nov' as in this month there was null in the site_count column.
I tried this following query and it worked,i.e. I got '0' in the site_count column for the month 'Nov' as you needed..
select month,count(site_count) from test ;

Answer 3

SELECT SUM(Hits) AS Hits,Month,MonthOrder
FROM
(
SELECT COUNT(siteCount) AS Hits,
DATE_FORMAT(TIMESTAMP,'%b') AS Month,
DATE_FORMAT(TIMESTAMP,'%m') AS MonthOrder
FROM count
WHERE redirectDomain LIKE 'http://domain.com'
AND DATE_FORMAT(TIMESTAMP,'%Y') = '2013'
AND DATE_FORMAT(TIMESTAMP,'%b') IN ('Sep','Oct','Nov')
GROUP BY DATE_FORMAT(TIMESTAMP,'%b')
UNION SELECT 0 AS Hits, 'Jan' AS Month,'01' AS MonthOrder
UNION SELECT 0 AS Hits, 'Feb' AS Month,'02' AS MonthOrder
UNION SELECT 0 AS Hits, 'Mar' AS Month,'03' AS MonthOrder
UNION SELECT 0 AS Hits, 'Apr' AS Month,'04' AS MonthOrder
UNION SELECT 0 AS Hits, 'May' AS Month,'05' AS MonthOrder
UNION SELECT 0 AS Hits, 'Jun' AS Month,'06' AS MonthOrder
UNION SELECT 0 AS Hits, 'Jul' AS Month,'07' AS MonthOrder
UNION SELECT 0 AS Hits, 'Aug' AS Month,'08' AS MonthOrder
UNION SELECT 0 AS Hits, 'Sep' AS Month,'09' AS MonthOrder
UNION SELECT 0 AS Hits, 'Oct' AS Month,'10' AS MonthOrder
UNION SELECT 0 AS Hits, 'Nov' AS Month,'11' AS MonthOrder
UNION SELECT 0 AS Hits, 'Dec' AS Month,'12' AS MonthOrder
)T1
GROUP BY Month,MonthOrder
ORDER BY MonthOrder ASC
delete your checking conditions as you see fit, i don't think you need the IN ('Sep','Oct','Nov') anymore it's up to you.
Here's the sqlFiddle example

Answer 4

you can't just count table only. below query might help you.
UPDATED
SELECT month_tab.Mo, IF(x.Hists IS NULL, 0, x.Hists)
FROM
(
SELECT 'Jan' AS Mo
UNION
SELECT 'Feb' AS Mo
UNION
SELECT 'Jun' AS Mo
UNION
SELECT 'Aug' AS Mo
UNION
SELECT 'Sep' AS Mo
UNION
SELECT 'Oct' AS Mo
UNION
SELECT 'Nov' AS Mo
) month_tab
LEFT JOIN
(
SELECT SUM(count.siteCount) AS Hists, DATE_FORMAT(timestamp, '%b') Mo
FROM count
WHERE redirectDomain LIKE 'http://domain.com'
GROUP BY Mo
) x ON month_tab.Mo = x.Mo;

Answer 5

Case is certainly an option...
SELECT
CASE WHEN
COUNT(`siteCount`) = 0
THEN
'0'
ELSE
COUNT(`siteCount`)
END AS Hits,
DATE_FORMAT(TIMESTAMP,'%b') AS Month
... but not necessary in this case (see full query with notes below):
SELECT
COUNT(`siteCount`) AS Hits,
-- See below for an explanation about naming conventions... 'TIMESTAMP' is probably
-- a name you'd want to avoid as well. If you can't avoid it though, use `backticks`.
DATE_FORMAT(`TIMESTAMP`,'%b') AS Month
-- I recommend changing the name of your database to something other than 'count'
-- because that can really confuse the system and make life much harder on you.
-- It's kind of like naming your daughter 'Daughter' or creating a PHP function
-- named 'function'. In either case you're eventually going to end up with a mess.
-- Fortunately, MySQL allows you to use `backticks` which, in this case, are
-- absolutely crucial (if for no other reason than maintaining sanity). ;)
FROM `count`
WHERE `redirectDomain` LIKE 'http://domain.com'
-- This will return a 4-digit numeric year (removing 'quotes')
AND DATE_FORMAT(`TIMESTAMP`,'%Y') = 2013
-- AND DATE_FORMAT(TIMESTAMP,'%b') BETWEEN 'Sep' AND 'Nov'
-- This doesn't know that you're talking about months... All it knows is to look
-- for values between the group of letters "Sep" and the group of letters "Nov".
-- For example, 'Feb' would not be counted as being between 'Jan' and 'Mar', because
-- it starts with the letter F, while 'Jul' and 'Jun' would.
-- Instead, convert to numbers:
AND DATE_FORMAT(`TIMESTAMP`,'%c') BETWEEN 9 AND 11
GROUP BY DATE_FORMAT(`TIMESTAMP`,'%b')
-- If you want the results ordered chronologically (instead of alphabetically) you
-- can use the same logic as is written above, converting letters to numbers.
-- However THIS time, use '%m' instead of '%c' because it will add a '0' to the
-- left of the month number. (Delete the next line if that's not what you want).
ORDER BY DATE_FORMAT(`TIMESTAMP`,'%m') ASC