3 개의 테이블과 날짜별로 그룹화하여 합계를 선택하는 SQL을 작성하는 방법

Question

3 개의 테이블이 있습니다. works, software는 agent

그것은 그렇게 보여

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agent :

id name 
1 agent1 
2 agent2 
3 agent3 
4 agent4 

works

id name date(TIMESTAMP type) agent_id 
1 w1 2014/1/1 1 
2 w2 2014/2/2 1 
3 w3 2014/1/3 2 
4 w4 2014/1/4 2 
5 w5 2014/1/5 3 
6 w6 2014/1/6 4 
7 w7 2014/1/7 4 
8 w8 2014/1/8 4 
9 w9 2014/3/9 4 

software

,617,

id name date(TIMESTAMP type) agent_id 
1 s1 2014/1/1 1 
2 s2 2014/2/2 1 
3 s3 2014/1/3 2 
4 s4 2014/1/4 2 
5 s5 2014/1/5 3 
6 s6 2014/1/6 4 
7 s7 2014/1/7 4 
8 s8 2014/1/8 4 
9 s9 2014/3/9 4 

---

와 나는 같은 결과를 얻으려면 : + 소프트웨어 작품의 현재 연도의 합계 매월

Jan-14 Feb-14 Mar-14 Apr-14 May-14 Jun-14 Jul-14 Aug-14 Sep-14 Oct-14 Nov-14 Dec-14 
agent1 2 2 0 0 0 0 0 0 0 0 0 0 
agent2 4 0 0 0 0 0 0 0 0 0 0 0 
agent3 2 0 0 0 0 0 0 0 0 0 0 0 
agent4 6 0 2 0 0 0 0 0 0 0 0 0 

AGENT_ID

으로 연결하는 방법 MySQL의에서 SQL을 쓸 수 있습니까?

Answer 1

이 시도 :

SELECT a.id, a.name, 
     SUM(CASE WHEN EXTRACT(YEAR_MONTH FROM w.date) = 201401 THEN 1 WHEN EXTRACT(YEAR_MONTH FROM s.date) = 201401 THEN 1 ELSE 0 END) AS Jan14, 
     SUM(CASE WHEN EXTRACT(YEAR_MONTH FROM w.date) = 201402 THEN 1 WHEN EXTRACT(YEAR_MONTH FROM s.date) = 201402 THEN 1 ELSE 0 END) AS Feb14, 
     SUM(CASE WHEN EXTRACT(YEAR_MONTH FROM w.date) = 201403 THEN 1 WHEN EXTRACT(YEAR_MONTH FROM s.date) = 201403 THEN 1 ELSE 0 END) AS Mar14, 
     SUM(CASE WHEN EXTRACT(YEAR_MONTH FROM w.date) = 201404 THEN 1 WHEN EXTRACT(YEAR_MONTH FROM s.date) = 201404 THEN 1 ELSE 0 END) AS Apr14, 
     SUM(CASE WHEN EXTRACT(YEAR_MONTH FROM w.date) = 201405 THEN 1 WHEN EXTRACT(YEAR_MONTH FROM s.date) = 201405 THEN 1 ELSE 0 END) AS May14, 
     SUM(CASE WHEN EXTRACT(YEAR_MONTH FROM w.date) = 201406 THEN 1 WHEN EXTRACT(YEAR_MONTH FROM s.date) = 201406 THEN 1 ELSE 0 END) AS Jun14, 
     SUM(CASE WHEN EXTRACT(YEAR_MONTH FROM w.date) = 201407 THEN 1 WHEN EXTRACT(YEAR_MONTH FROM s.date) = 201407 THEN 1 ELSE 0 END) AS Jul14, 
     SUM(CASE WHEN EXTRACT(YEAR_MONTH FROM w.date) = 201408 THEN 1 WHEN EXTRACT(YEAR_MONTH FROM s.date) = 201408 THEN 1 ELSE 0 END) AS Aug14, 
     SUM(CASE WHEN EXTRACT(YEAR_MONTH FROM w.date) = 201409 THEN 1 WHEN EXTRACT(YEAR_MONTH FROM s.date) = 201409 THEN 1 ELSE 0 END) AS Sep14, 
     SUM(CASE WHEN EXTRACT(YEAR_MONTH FROM w.date) = 201410 THEN 1 WHEN EXTRACT(YEAR_MONTH FROM s.date) = 201410 THEN 1 ELSE 0 END) AS Oct14, 
     SUM(CASE WHEN EXTRACT(YEAR_MONTH FROM w.date) = 201411 THEN 1 WHEN EXTRACT(YEAR_MONTH FROM s.date) = 201411 THEN 1 ELSE 0 END) AS Nov14, 
     SUM(CASE WHEN EXTRACT(YEAR_MONTH FROM w.date) = 201412 THEN 1 WHEN EXTRACT(YEAR_MONTH FROM s.date) = 201412 THEN 1 ELSE 0 END) AS Dec14 
FROM agent a 
LEFT OUTER JOIN works w ON a.id = w.agent_id 
LEFT OUTER JOIN software s ON a.id = s.agent_id 
GROUP BY a.id;