# $1549. 每件商品的最新订单
# https://leetcode-cn.com/problems/the-most-recent-orders-for-each-product/

# SQL架构
Create table If Not Exists Customers (customer_id int, name varchar(10));
Create table If Not Exists Orders (order_id int, order_date date, customer_id int, product_id int);
Create table If Not Exists Products (product_id int, product_name varchar(20), price int);
Truncate table Customers;
insert into Customers (customer_id, name) values ('1', 'Winston');
insert into Customers (customer_id, name) values ('2', 'Jonathan');
insert into Customers (customer_id, name) values ('3', 'Annabelle');
insert into Customers (customer_id, name) values ('4', 'Marwan');
insert into Customers (customer_id, name) values ('5', 'Khaled');
Truncate table Orders;
insert into Orders (order_id, order_date, customer_id, product_id) values ('1', '2020-07-31', '1', '1');
insert into Orders (order_id, order_date, customer_id, product_id) values ('2', '2020-7-30', '2', '2');
insert into Orders (order_id, order_date, customer_id, product_id) values ('3', '2020-08-29', '3', '3');
insert into Orders (order_id, order_date, customer_id, product_id) values ('4', '2020-07-29', '4', '1');
insert into Orders (order_id, order_date, customer_id, product_id) values ('5', '2020-06-10', '1', '2');
insert into Orders (order_id, order_date, customer_id, product_id) values ('6', '2020-08-01', '2', '1');
insert into Orders (order_id, order_date, customer_id, product_id) values ('7', '2020-08-01', '3', '1');
insert into Orders (order_id, order_date, customer_id, product_id) values ('8', '2020-08-03', '1', '2');
insert into Orders (order_id, order_date, customer_id, product_id) values ('9', '2020-08-07', '2', '3');
insert into Orders (order_id, order_date, customer_id, product_id) values ('10', '2020-07-15', '1', '2');
Truncate table Products;
insert into Products (product_id, product_name, price) values ('1', 'keyboard', '120');
insert into Products (product_id, product_name, price) values ('2', 'mouse', '80');
insert into Products (product_id, product_name, price) values ('3', 'screen', '600');
insert into Products (product_id, product_name, price) values ('4', 'hard disk', '450');

# Write your MySQL query statement below
select
    p.product_name,
    tmp.product_id,
    tmp.order_id,
    tmp.order_date
from
    Products p
    join (
        select
            product_id,
            order_id,
            order_date,
            # dense_rank() 亦可
            rank() over (
                partition by product_id
                order by
                    order_date desc
            ) as _rank
        from
            Orders
    ) tmp on p.product_id = tmp.product_id
where
    tmp._rank = 1
order by
    p.product_name,
    tmp.product_id,
    tmp.order_id;

# clean-up
drop table Customers;
drop table Orders;
drop table Products;