MySQL 8.0

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create table tblProjects (proj_id int, proj_title varchar(20), proj_cat int, proj_sdate date);
insert into tblProjects values
(1, 'Projects X', 3, '2018-11-15'),
(2, 'Projects Y', 2, '2018-11-01'),
(3, 'Projects Z', 1, '2018-12-05'),
(4, 'Projects XYZ', 3, '2017-12-01'),
(5, 'Projects Satu', 3, '2018-12-01')

Records: 5  Duplicates: 0  Warnings: 0


create table tblCategory (cat_id int, cat_title varchar(20));
insert into tblCategory values
(1, 'Trip'),
(2, 'Sports'),
(3, 'KSS Talks')

Records: 3  Duplicates: 0  Warnings: 0


create table tblExpenses (exp_id int, projects_id int, exp_amount decimal(10,2))
insert into tblExpenses values
(1, 1, 200),
(2, 1, 165),
(3, 4, 152)

Records: 3  Duplicates: 0  Warnings: 0


create table tblIncome (inc_id int, projects_id int, inc_amount decimal(10,2))
insert into tblIncome values
(1, 1, 250),
(2, 1, 21),
(3, 2, 100),
(4, 3, 15),
(5, 2, 50),
(6, 4, 2),
(7, 5, 100)

Records: 7  Duplicates: 0  Warnings: 0


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


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

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