# 1795. 每个产品在不同商店的价格
# https://leetcode-cn.com/problems/rearrange-products-table/

# SQL架构
Create table If Not Exists Products (product_id int, store1 int, store2 int, store3 int);
Truncate table Products;
insert into Products (product_id, store1, store2, store3) values ('0', '95', '100', '105');
insert into Products (product_id, store1, store2, store3) values ('1', '70', null, '80');

# Write your MySQL query statement below
select
    product_id,
    'store1' as store,
    store1 as price
from
    Products
where
    store1 is not null
union
all
select
    product_id,
    'store2' as store,
    store2 as price
from
    Products
where
    store2 is not null
union
all
select
    product_id,
    'store3' as store,
    store3 as price
from
    Products
where
    store3 is not null;

# clean-up
drop table Products;