使用GROUP BY进行MYSQL LEFT JOIN

Question

:)我有2个查询,我需要加入他们,我需要根据活动将员工的工作时间与定义期间同一活动中公司的总工作时间进行比较

第一个查询是:

SELECT u.login,
       a.article, 
       p.p_article, 
       (SUM(p.p_going) + SUM(p.p_leaving) + SUM(p.p_working)) AS tottime
FROM pos p,users u, articles a
WHERE u.login = p.p_login
AND REPLACE( u.login, '.', '_' ) = 'users_name'
AND p.p_datum >= '2013-04-09'
AND p.p_datum <= '2013-04-16'
AND p.p_article = a.id
GROUP BY a.article

我的第二个问题是:

SELECT a.article, 
       p.p_article, 
       (SUM(p.p_going) + SUM(p.p_leaving) + SUM(p.p_working)) AS tottime
FROM pos p, articles a
WHERE p.p_datum >= '2013-04-09'
AND p.p_datum <= '2013-04-16'
AND p.p_article = a.id
GROUP BY a.article

第一个查询返回按活动分组的WORKER总工作时间,例如:

u.login    a.article     p.p_article  tottime
Ivan       Teambuilding    1          3,45
Julie      Social_work     2          5,67

第二个查询返回按活动分组的COMPANY的总工作时间,例如:

a.article     p.p_article  tottime
Teambuilding    1         150
Social_work     2         260

我想要这样的东西,所以我可以将每个活动的工人总时间与特定时期内每个活动的公司工作时间总时间进行比较:

u.login    a.article     p.p_article  tottime(worker)  tottime(company) 
Ivan       Teambuilding    1          3,45              150  
Julie      Social_work     2          5,67              260

如果是NULL值,我想使用LEFT JOIN.我正在寻找解决方案3个小时,我尝试的一切都不起作用,所以任何帮助将不胜感激.

Answer 1

您可以将两个查询作为一对子选择一起加入.

就像是:-

SELECT Sub1.a, Sub1.b, Sub2.c
FROM (SELECT a, b FROM z) Sub1
INNER JOIN (SELECT a, c FROM y) Sub2
ON Sub1.a = Sub2.a

但是不能真正给你更多,因为你的第一个例子查询似乎没有带回你说的细节(只带回3列).

编辑 - 使用更正的查询

SELECT Sub1.login AS User_name, Sub1.article AS Activity, Sub1.p_article AS `Activity id`, Sub1.tottime AS `Totaltime(worker)`, Sub2.tottime AS `Totaltime(company)`
FROM (SELECT u.login,a.article, p.p_article, (SUM(p.p_going) + SUM(p.p_leaving) + SUM(p.p_working)) AS tottime
FROM pos p
INNER JOIN users u ON u.login = p.p_login 
INNER JOIN articles a ON p.p_article = a.id
WHERE REPLACE( u.login, '.', '_' ) = 'users_name'
AND p.p_datum >= '2013-04-09'
AND p.p_datum <= '2013-04-16'
GROUP BY a.article) Sub1
INNER JOIN 
(SELECT a.article, p.p_article, (SUM(p.p_going) + SUM(p.p_leaving) + SUM(p.p_working)) AS tottime
FROM pos p
INNER JOIN articles a ON p.p_article = a.id
WHERE p.p_datum >= '2013-04-09'
AND p.p_datum <= '2013-04-16'
GROUP BY a.article) Sub2
ON Sub1.p_article = Sub2.p_article