Question

我正在研究费用/预算跟踪系统，并且陷入其中。
我有四张桌子
tblProjects

tblCategory

tblExpenses

tbl收入

tblProject与1：1的tblCategory相关，

tblExpenses与1：1的tblProject有关，

tbl收入与1：1的tblProjects有关

我正在尝试按年份（从tblProjects.proj_sdate列中获得每个类别组的费用和收入之和），以及一列显示损益（费用-收入）。
例如，我想知道什么是总支出，总收入，旅行，体育等方面的损益的价值？
下面是我要实现的示例；

我设法提出了以下两个查询，将收入和支出分开。但不确定如何组合使其成为单个查询并执行减法运算以获取损益值。

1)Incomes
SELECT category.cat_title as Category, group_concat(distinct 
projects.proj_title) as Projects, date_format(projects.proj_sdate, '%Y') as 
Year, sum(incomes.inc_amount) as Total_Incomes from category inner join 
projects on projects.proj_cat = category.cat_id inner join incomes on 
incomes.projects_id = projects.proj_id group by category.cat_title, 
date_format(projects.proj_sdate, '%Y')

2)Expenses
SELECT category.cat_title as Category, group_concat(distinct 
projects.proj_title) as Projects, date_format(projects.proj_sdate, '%Y') as 
Year, sum(expenses.exp_amount) as Total_Expenses from category inner join 
projects on projects.proj_cat = category.cat_id inner join expenses on 
expenses.projects_id = projects.proj_id group by category.cat_title, 
date_format(projects.proj_sdate, '%Y')

Answer 1

我认为此查询将为您提供所需的结果。因为每个项目可以有多个支出和收入行，所以需要JOIN来汇总收入和支出表（按项目）而不是原始表。然后，将所有JOIN的结果按Category和Year分组：

SELECT c.cat_title AS Category,
       GROUP_CONCAT(p.proj_title) AS Projects,
       YEAR(p.proj_sdate) AS Year,
       COALESCE(SUM(i.income), 0) AS Total_Income,
       COALESCE(SUM(e.expenses), 0) AS Total_Expenses,
       COALESCE(SUM(i.income), 0) - COALESCE(SUM(e.expenses), 0) AS `P&L`
FROM tblCategory c
JOIN tblProjects p ON p.proj_cat = c.cat_id
LEFT JOIN (SELECT projects_id, SUM(exp_amount) AS expenses
           FROM tblExpenses 
           GROUP BY projects_id) e ON e.projects_id = p.proj_id
LEFT JOIN  (SELECT projects_id, SUM(inc_amount) AS income
           FROM tblIncome
           GROUP BY projects_id) i ON i.projects_id = p.proj_id
GROUP BY Category, Year

结果（针对您问题中的示例数据）：

Category    Projects                    Year    Total_Income    Total_Expenses  P&L
KSS Talks   Projects XYZ                2017    2.00            152.00          -150.00
KSS Talks   Projects X,Projects Satu    2018    371.00          365.00          6.00
Sports      Projects Y                  2018    150.00          0.00            150.00
Trip        Projects Z                  2018    15.00           0.00            15.00

Demo on dbfiddle

Answer 2

您可以在下面尝试

SELECT category.cat_title as Category, group_concat(distinct 
projects.proj_title) as Projects, date_format(projects.proj_sdate, '%Y') as 
Year, sum(incomes.inc_amount) as Total_Incomes,
sum(expenses.exp_amount) as Total_Expenses,
sum(incomes.inc_amount) -  sum(expenses.exp_amount) as PL
from category inner join projects on projects.proj_cat = category.cat_id 
inner join expenses on expenses.projects_id = projects.proj_id
inner join incomes on incomes.projects_id = projects.proj_id
group by category.cat_title, 
date_format(projects.proj_sdate, '%Y')

从另一个表获取2个不同表的SUM

2 个答案: