将合并和求和与不同的列合并

Question

我在这里查看

我想尝试的是使v_total_project看起来像这样。 我尝试过此代码

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 。 所以我尝试了联盟打印两个id_project，并得到错误的列数不同。

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，还有另一种方法吗？ 提前致谢，

Answer 1

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

在您的工会的第一次选择中，您缺少要支付的费用的字段。

联接也丢失了，添加了它。 而不是INNER JOIN使用LEFT或RIGHT Join ，否则您只会获得两个表中id_project的结果。

在计算中添加了ifnull() ，因为LEFT / RIGHT连接可以返回null ，必须将其视为0。