Subqueries and Combining Queries together - postgresql

Question

I have a problem I've been working on. I've broken it down to a couple of steps below. I have trouble combining all the queries together to solve the following:
Find members who have spent over $1000 in departments that have
brought in more than $10000 total ordered by the members' id.
Schema:
departments(id, name)
products (id, name, price)
members(id, name, number, email, city, street_name, street_address)
sales(id, department_id, product_id, member_id, transaction_date
Step 1)
I found the departments that have brought in more than 10,000$
select s.department_id
from sales s join products p on
s.product_id = p.id
group by s.department_id
having sum(price) > '10000'
Step 2) I found the members and the departments that they shop in
select *
from members m
join sales s
on m.id = s.member_id
join departments d
on d.id = s.department_id
Step 3) I combined 1 and 2 to find members taht shop in departments that have brought in more than 10,000
select *
from members m
join sales s
on m.id = s.member_id
join departments d
on d.id = s.department_id
where s.department_id in
(select s.department_id
from sales s join products p on
s.product_id = p.id
group by s.department_id
having sum(price) > '10000')
Step 4) I found members and their id, email, total_spending > 1,000$
select m.id, m.name, m.email, sum(price) as total_spending
from members m join sales s on
m.id = s.member_id
join products p on
p.id = s.product_id
group by m.id
having sum(price) > '1000'
Step 5)
All of the steps work individually but when I put them together in my attempt:
select m.id, m.name, m.email, sum(price) as total_spending
from members m join sales s on
m.id = s.member_id
join products p on
p.id = s.product_id
where m.id in (select distinct m.id
from members m
join sales s
on m.id = s.member_id
join departments d
on d.id = s.department_id
where s.department_id in
(select s.department_id
from sales s join products p on
s.product_id = p.id
group by s.department_id
having sum(price) > '10000'))
group by m.id
having sum(price) > '1000'
The output is wrong. (This is on CodeWars) If someone could point me in the right direction that would be really great! Thank you.

Answer 1

Try to group by member_id and department_id:
select s.member_id,s.department_id,sum(p.price) as total_spending
from members m
join sales s on m.id = s.member_id
join products p on p.id = s.product_id
where s.department_id in (
select s.department_id
from sales s
join products p on s.product_id = p.id
group by s.department_id
having sum(p.price) > 10000 -- the departments which brought in more than $10000 total
)
group by s.member_id,s.department_id
having sum(p.price) > 1000 -- who have spent over $1000 in one department
And if you need you will able to calc how much spent each of members:
select member_id,sum(total_spending) total
from
(
-- the first query is here
) q
group by member_id