Count() does not return zero MySQL - mysql

Question

I am a web developer and tried to search for the solution on a mysql query.I am unable to get the right solution for the count() function to return zero.
The count() function doesnot return zero for all dates.
The query is as below . can anyone help me on this.
SELECT
count(stat_id) as typeSuccess,
device_type as typeName,
YEARWEEK(date_auth) as date
FROM auth_stat
WHERE
AUTH_RESULT = 'SUCCESS' AND
date_auth BETWEEN DATE_SUB(CURDATE(), INTERVAL 6 WEEK) AND CURDATE()
GROUP BY YEARWEEK(date_auth), device_type
ORDER BY YEARWEEK(date_auth)
The query that i tried to form is
select
date_auth,
count(stat_id) as typeSuccess,
device_type as typeName,
YEARWEEK(date_auth) as date
from
(
select #curDate := Date_Add(#curDate, interval 1 day) as MyJoinDate
from
(
select #curDate := CURDATE()
) sqlvars, auth_stat limit 18
) dateAll
LEFT JOIN auth_stat U on dateAll.MyJoinDate = U.date_auth
group by dateAll.MyJoinDate
Actual ouput :
+------------+-------------+
| date | typeSuccess |
+------------+-------------+
| 2015-03-18 | 11 |
+------------+-------------+
Expected Output:
+------------+-------------+
| date | typeSuccess |
+------------+-------------+
| 2015-03-18 | 11 |
| 2015-03-19 | 0 |
| 2015-03-20 | 0 |
+------------+-------------+

Answer 1

I believe all you want to do is just this
SELECT
SUM(AUTH_RESULT='SUCCESS') as numSuccess,
YEARWEEK(date_auth) as date
FROM auth_stat
WHERE date_auth BETWEEN DATE_SUB(CURDATE(), INTERVAL 6 WEEK) AND CURDATE()
GROUP BY YEARWEEK(date_auth), device_type
ORDER BY YEARWEEK(date_auth)
basically all i'm doing is telling MySQL to sum up the boolean value (0 or 1) when auth_result is a success.. SUM() will return a 0 for a particular week if there is no successes in that week
The main issue is you were filtering out all non successful auth_results which would then not be counted. so remove that from the where and you should be good!
if you want it per day then you can do this
SELECT
SUM(AUTH_RESULT='SUCCESS') as numSuccess,
DATE(date_auth) as date
FROM auth_stat
WHERE date_auth BETWEEN DATE_SUB(CURDATE(), INTERVAL 6 WEEK) AND CURDATE()
GROUP BY DATE(date_auth), device_type
ORDER BY DATE(date_auth)
SQLFIDDLE FOR BOTH RESULTS

Answer 2

try
SELECT COUNT(statid), dates.auth_date
FROM
( SELECT DISTINCT auth_date
FROM Table1
WHERE auth_date BETWEEN '2015-03-06' AND '2015-03-09' -- or whatever
) AS dates
LEFT JOIN Table1 ON TRUE
AND Table1.auth_date = dates.auth_date
AND table1.auth_result = 'SUCCESS'
GROUP BY dates.auth_date
ORDER BY dates.auth_date
as desribed here: http://sqlfiddle.com/#!9/84faf/2
for eg data:
+--------+-------------+------------+
| statid | auth_result | auth_date |
+--------+-------------+------------+
| 1 | SUCCESS | 2015-03-05 |
| 2 | SUCCESS | 2015-03-05 |
| 3 | SUCCESS | 2015-03-05 |
| 4 | OTHER | 2015-03-06 |
| 5 | OTHER | 2015-03-06 |
| 6 | OTHER | 2015-03-06 |
| 7 | SUCCESS | 2015-03-07 |
| 8 | SUCCESS | 2015-03-07 |
| 9 | SUCCESS | 2015-03-07 |
| 10 | OTHER | 2015-03-08 |
| 11 | SUCCESS | 2015-03-08 |
| 12 | OTHER | 2015-03-08 |
| 13 | SUCCESS | 2015-03-09 |
| 14 | SUCCESS | 2015-03-09 |
| 15 | SUCCESS | 2015-03-09 |
| 16 | OTHER | 2015-03-10 |
| 17 | OTHER | 2015-03-10 |
| 18 | SUCCESS | 2015-03-10 |
| 19 | OTHER | 2015-03-11 |
+--------+-------------+------------+
eg output:
+---------------+-------------------------+
| count(statid) | auth_date |
+---------------+-------------------------+
| 0 | March, 06 2015 00:00:00 |
| 3 | March, 07 2015 00:00:00 |
| 1 | March, 08 2015 00:00:00 |
| 3 | March, 09 2015 00:00:00 |
+---------------+-------------------------+

Answer 3

It is not beautiful but hope it helps:
SELECT
date_auth,
count(stat_id) as typeSuccess,
device_type as typeName,
YEARWEEK(date_auth) as date
FROM
(
SELECT
DATE(DATE_ADD(NOW(), interval tmp.id day)) AS MyJoinDate
FROM (SELECT 1 as id
UNION ALL SELECT 2
UNION ALL SELECT 3
UNION ALL SELECT 4
UNION ALL SELECT 5
UNION ALL SELECT 6
UNION ALL SELECT 7
UNION ALL SELECT 8
UNION ALL SELECT 9
UNION ALL SELECT 10
UNION ALL SELECT 11
UNION ALL SELECT 12
UNION ALL SELECT 13
UNION ALL SELECT 14
UNION ALL SELECT 15
UNION ALL SELECT 16
UNION ALL SELECT 17
UNION ALL SELECT 18
) AS tmp
) dateAll
LEFT JOIN auth_stat U on dateAll.MyJoinDate = U.date_auth
group by dateAll.MyJoinDate

Answer 4

I have tried adding the query as below. It stills returns me records that have the counts and not the dates with the count as zero.
SELECT COUNT(stat_id), dates.date_auth
FROM
( SELECT DISTINCT date_auth
FROM auth_stat
WHERE date_auth BETWEEN DATE_SUB(CURDATE(), INTERVAL 20 DAY) AND CURDATE()
) AS dates
LEFT JOIN auth_stat ON TRUE
AND auth_stat.date_auth = dates.date_auth
AND auth_stat.auth_result = 'SUCCESS'
GROUP BY dates.date_auth
ORDER BY dates.date_auth
Output result for the above query:
COUNT(stat_id) date_auth Ascending 1
1 2015-03-05 00:00:00
1 2015-03-06 00:00:00
11 2015-03-18 00:00:00