SQL Tutorials - Count Apples and Oranges - Part 33

Leetcode Question 1715
Count Apples and Oranges

Table: Boxes

+--------------+------+
| Column Name | Type |
+--------------+------+
| box_id | int |
| chest_id | int |
| apple_count | int |
| orange_count | int |
+--------------+------+
box_id is the primary key for this table.
chest_id is a foreign key of the chests table.
This table contains information about the boxes and the number of oranges and apples they contain. Each box may contain a chest, which also can contain oranges and apples.
Table: Chests

+--------------+------+
| Column Name | Type |
+--------------+------+
| chest_id | int |
| apple_count | int |
| orange_count | int |
+--------------+------+
chest_id is the primary key for this table.
This table contains information about the chests we have, and the corresponding number if oranges and apples they contain.
Write an SQL query to count the number of apples and oranges in all the boxes. If a box contains a chest, you should also include the number of apples and oranges it has.

Return the result table in any order.

The query result format is in the following example:

Boxes table:
+--------+----------+-------------+--------------+
| box_id | chest_id | apple_count | orange_count |
+--------+----------+-------------+--------------+
| 2 | null | 6 | 15 |
| 18 | 14 | 4 | 15 |
| 19 | 3 | 8 | 4 |
| 12 | 2 | 19 | 20 |
| 20 | 6 | 12 | 9 |
| 8 | 6 | 9 | 9 |
| 3 | 14 | 16 | 7 |
+--------+----------+-------------+--------------+

Chests table:
+----------+-------------+--------------+
| chest_id | apple_count | orange_count |
+----------+-------------+--------------+
| 6 | 5 | 6 |
| 14 | 20 | 10 |
| 2 | 8 | 8 |
| 3 | 19 | 4 |
| 16 | 19 | 19 |
+----------+-------------+--------------+

Result table:
+-------------+--------------+
| apple_count | orange_count |
+-------------+--------------+
| 151 | 123 |
+-------------+--------------+
box 2 has 6 apples and 15 oranges.
box 18 has 4 + 20 (from the chest) = 24 apples and 15 + 10 (from the chest) = 25 oranges.
box 19 has 8 + 19 (from the chest) = 27 apples and 4 + 4 (from the chest) = 8 oranges.
box 12 has 19 + 8 (from the chest) = 27 apples and 20 + 8 (from the chest) = 28 oranges.
box 20 has 12 + 5 (from the chest) = 17 apples and 9 + 6 (from the chest) = 15 oranges.
box 8 has 9 + 5 (from the chest) = 14 apples and 9 + 6 (from the chest) = 15 oranges.
box 3 has 16 + 20 (from the chest) = 36 apples and 7 + 10 (from the chest) = 17 oranges.
Total number of apples = 6 + 24 + 27 + 27 + 17 + 14 + 36 = 151
Total number of oranges = 15 + 25 + 8 + 28 + 15 + 15 + 17 = 123