mysql – What is the query-join alternative

Table: goods

+ --- + ----------- +
| id | name |
+ --- + ----------- +
| 1 | Product-A |
+ --- + ----------- +
| 2 | Product-b |
+ --- + ----------- +

Table: orders

+ --- + ----- + ------------ +
| id | price | orderer_id |
+ --- + ----- + ------------ +
| 1 | 100 | 53 |
+ --- + ----- + ------------ +
| 2 | 240 | 54 |
+ --- + ----- + ------------ +
| 3 | 200 | 54 |
+ --- + ----- + ------------ +
| 4 | 150 | 53 |
+ --- + ----- + ------------ +

Table: item_order

+ ---- + -------- + --------- + ---------- +
| id | order_id | item_id | quantity |
+ ---- + -------- + --------- + ---------- +
| 1 | 1 | 1 | 2 |
+ ---- + -------- + --------- + ---------- +
| 2 | 1 | 2 | 3 |
+ ---- + -------- + --------- + ---------- +
| 3 | 2 | 2 | 2 |
+ ---- + -------- + --------- + ---------- +
| 4 | 3 | 1 | 1 |
+ ---- + -------- + --------- + ---------- +
| 5 | 3 | 2 | 1 |
+ ---- + -------- + --------- + ---------- +
| 6 | 4 | 1 | 2 |
+ ---- + -------- + --------- + ---------- +
| 7 | 4 | 2 | 2 |
+ ---- + -------- + --------- + ---------- +

What to extract:

For each orderer_id, order number, total quantity, total price

+ --------- + ----------------- + ---------------- + ---- --------- +
| donor | order_number | total_quantity | total_price |
+ --------- + ----------------- + ---------------- + ---- --------- +
| 53 | 2 | 9 | 250 |
+ --------- + ----------------- + ---------------- + ---- --------- +
| 54 | 2 | 4 | 440 |
+ --------- + ----------------- + ---------------- + ---- --------- +

Current approach:
Use a subquery

select orderer_id as the ordering party,
count (*) as number_order,
sum (select quantity in item_order or item_order.order_id = orders.id) as total_quantity,
sum (price) as total_price
orders
order by orderer_id

Can it be solved by joining item_order with orders ? If yes, how?

Another approach I thought –

  1. select … commands
  2. select … from item_order
  3. combine and format as required in the application layer

As you can imagine, orders and item_order table will become much bigger, which solution will be the best?