SQL SUM operation of multiple subqueries

Question

i have the following mysql database table designed,

ticket(id, code, cust_name);
passenger(id, ticket_id, name, age, gender, fare);
service(id, passenger_id,         


        

Answer 1

select
    t.code,
    sum(p.fare) as total_fare,
    sum(s.cost) as total_cost
from ticket as t
    inner join passenger as p on p.ticket_id = t.id
    inner join service as s on s.passenger_id = p.id
group by t.code