将 union 和 sum 与不同的视图列结合起来

Combine union and sum with diffrent column of view

我在这里查看

我想尝试的是让 v_total_project 看起来像那样。 我试过这个代码

select o.id_project AS id_project,
sum((o.office_expense + m.misc_expense)) AS total_expense 
from v_office_project o inner join v_misc_project m on o.id_project = m.id_project
group by o.id_project, m.id_project

我知道我的代码不会打印 v_misc_project.id_project。所以我尝试使用 Union 打印两个 id_project,但得到了不同列数的错误。

select o.id_project AS id_project
from v_office_project o
union
select m.id_project as id_project,
sum((o.office_expense + m.misc_expense)) AS total_expense 
from v_office_project o inner join v_misc_project m on o.id_project = m.id_project
group by id_project

那么,还有其他方法吗? 提前致谢,

SELECT
    o.id_project AS id_project,
    sum(
        o.office_expense + ifnull(m.misc_expense, 0)
    ) AS total_expense
FROM
    v_office_project o
LEFT JOIN v_misc_project m ON o.id_project = m.id_project
GROUP BY
    id_project
UNION
    SELECT
        m.id_project AS id_project,
        sum(
            ifnull(o.office_expense, 0) + m.misc_expense
        ) AS total_expense
    FROM
        v_office_project o
    RIGHT JOIN v_misc_project m ON o.id_project = m.id_project
    GROUP BY
        id_project

在你的工会的第一个 select 中,你缺少费用字段。

还缺少连接,添加它。而不是 INNER JOIN 使用 LEFTRIGHT Join,否则你只会得到两个表中的 id_project 的结果。

在计算中添加了ifnull(),因为LEFT / RIGHT joins 可以return null,必须将其视为0.