Count invitation response against events and response codes - mysql

Question

I have this table for Response Codes:
And this table for invitations:
My query so far gives this:
While I want to achieve this:
MY QUERY:
SELECT
i.eventId
,code.responseCode
,COUNT(i.attendeeResponse) responseCount
FROM invitations i
LEFT JOIN response_codes code
ON code.responseCode = i.attendeeResponse
GROUP BY i.eventId, code.responseCode, i.attendeeResponse;
SQLFiddle

Answer 1

You need to construct a cartesian product of all eventIds and responseCodes at first (you can achieve it with join without condition):
select c.eventId
, c.responseCode
, count( i.attendeeResponse ) as responseCount
from ( select distinct t1.responseCode
, t2.eventId
from `response_codes` t1
join `invitations` t2 ) c
left join `invitations` i on c.responseCode = i.attendeeResponse and c.eventId = i.eventId
group by c.eventId, c.responseCode;
SQLFiddle

Answer 2

You need to cross join the responsecode table to get the all combinations of eventid and responsecode.
SQL Fiddle
SELECT distinct
i.eventId
,code.responseCode
,case when t.responseCount is null then 0
else t.responsecount end rcount
FROM invitations i
cross JOIN response_codes code
left join
(SELECT i.eventId
,code.responseCode
,COUNT(i.attendeeResponse) responseCount
FROM invitations i
JOIN response_codes code
ON code.responseCode = i.attendeeResponse
group by i.eventid, code.responsecode) t
on t.responsecode =code.responsecode and t.eventid = i.eventid
order by i.eventid, code.responsecode desc

Answer 3

Another lazy way could be:
SELECT B.EVENTID,A.RESPONSECODE,
IFNULL((SELECT COUNT(*) FROM INVITATIONS C WHERE C.EVENTID = B.EVENTID AND C.ATTENDEERESPONSE = A.RESPONSECODE),0) AS 'responseCount'
FROM
RESPONSE_CODES A,
INVITATIONS B
GROUP BY A.RESPONSECODE,B.EVENTID
ORDER BY EVENTID ASC,RESPONSECODE DESC
SQL Fiddle