Question

我有以下两个问题：

    Select count(project.id) as num_project , 
           industry.name as industry_name 
    from   project, project_industry, industry 
    where  industry.id= project_industry.industry_id and 
           project.id = project_industry.project_id  
    group by industry.id;

Select count(user.id) as num_consultants , 
       industry.name as industry_name 
from   consultant_profile, industry_experience,user, industry 
where  industry_experience.consultant_profile_id = consultant_profile.id
       and industry_experience.industry_id= industry.id 
       and user.type=0 
       and user.is_active=1 
       and consultant_profile.user_id=user.id 
group by industry_id;

我试图将它们组合成一个如下：

SELECT i.name AS industry_name, num_projects, num_consultants
FROM   industry i
JOIN   (SELECT   pc.industry_id, COUNT(p.id) AS num_projects
        FROM     project p
        JOIN     project_industry pc ON p.id = pc.project_id
        GROUP BY pc.industry_id) x ON x.industry_id = i.id
JOIN   (SELECT   y.industry_id, COUNT(u.id) AS num_consultants
        FROM     user u, consultant_profile cp
        JOIN     project_experience pe on pe.consultant_profile_id = cp.id
        WHERE    u.is_active = 1 AND u.type = 0
        GROUP BY y.industry_id) z ON z.industry_id = i.id;

但它似乎不起作用。谁能指出我做错了什么？非常感谢任何帮助。

编辑：要明确第一个查询显示与每个行业相关的项目数量。第二个查询显示与每个行业相关的顾问数量。

我希望第三个查询在3个单独的列中显示同一个表中前两个查询的信息：行业名称，＃项目，＃顾问

表结构如下，其中 - ＆gt;描述了表的主键和外键：

Project -> project.id
Project_industry -> project_industry.id, project_id, industry_id
Industry -> industry.id

user -> user.id
Consultant_profile -> consultant_profile.id, user_id
Industry_Experience -> industry_experience.id, consultant_profile_id, industry_id
Industry -> industry.id

Answer 1

你几乎就在那里。根据我的理解，下面的查询应该适合你。

QUERY

select T1.industry_name ,num_project ,num_consultants  from 
( Select count(project.id) as num_project , industry.name as industry_name ,industry.id as id  from project, project_industry, industry where industry.id= project_industry.industry_id and project.id = project_industry.project_id  group by industry.id ) T1 
JOIN 
 ( Select count(user.id) as num_consultants , industry.name as industry_name,industry.id as id from consultant_profile, industry_experience,user, industry where industry_experience.consultant_profile_id = consultant_profile.id and industry_experience.industry_id= industry.id and user.type=0 and user.is_active=1 and consultant_profile.user_id=user.id group by industry_id ) T2 
ON T1.id = T2.id

SQL：将两个查询合并为一个查询

1 个答案: