Table: Products
+-------------+---------+ | Column Name | Type | +-------------+---------+ | product_id | int | | store_name1 | int | | store_name2 | int | | : | int | | : | int | | : | int | | store_namen | int | +-------------+---------+ product_id is the primary key for this table. Each row in this table indicates the product's price in n different stores. If the product is not available in a store, the price will be null in that store's column. The names of the stores may change from one testcase to another. There will be at least 1 store and at most 30 stores.
Important note: This problem targets those who have a good experience with SQL. If you are a beginner, we recommend that you skip it for now.
Implement the procedure UnpivotProducts to reorganize the Products table so that each row has the id of one product, the name of a store where it is sold, and its price in that store. If a product is not available in a store, do not include a row with that product_id and store combination in the result table. There should be three columns: product_id, store, and price.
The procedure should return the table after reorganizing it.
Return the result table in any order.
The query result format is in the following example.
Example 1:
Input: Products table: +------------+----------+--------+------+------+ | product_id | LC_Store | Nozama | Shop | Souq | +------------+----------+--------+------+------+ | 1 | 100 | null | 110 | null | | 2 | null | 200 | null | 190 | | 3 | null | null | 1000 | 1900 | +------------+----------+--------+------+------+ Output: +------------+----------+-------+ | product_id | store | price | +------------+----------+-------+ | 1 | LC_Store | 100 | | 1 | Shop | 110 | | 2 | Nozama | 200 | | 2 | Souq | 190 | | 3 | Shop | 1000 | | 3 | Souq | 1900 | +------------+----------+-------+ Explanation: Product 1 is sold in LC_Store and Shop with prices of 100 and 110 respectively. Product 2 is sold in Nozama and Souq with prices of 200 and 190. Product 3 is sold in Shop and Souq with prices of 1000 and 1900.