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Description

Table: Products

+-------------+---------+

| Column Name | Type    |

+-------------+---------+

| product_id  | int     |

| store1      | int     |

| store2      | int     |

| store3      | int     |

+-------------+---------+

product_id is the primary key for this table.

Each row in this table indicates the product's price in 3 different stores: store1, store2, and store3.

If the product is not available in a store, the price will be null in that store's column.

 

Write an SQL query to rearrange the Products table so that each row has (product_id, store, price). 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.

Return the result table in any order.

The query result format is in the following example:

 

Products table:

+------------+--------+--------+--------+

| product_id | store1 | store2 | store3 |

+------------+--------+--------+--------+

| 0          | 95     | 100    | 105    |

| 1          | 70     | null   | 80     |

+------------+--------+--------+--------+



Result table:

+------------+--------+-------+

| product_id | store  | price |

+------------+--------+-------+

| 0          | store1 | 95    |

| 0          | store2 | 100   |

| 0          | store3 | 105   |

| 1          | store1 | 70    |

| 1          | store3 | 80    |

+------------+--------+-------+



Product 0 is available in all three stores with prices 95, 100, and 105 respectively.

Product 1 is available in store1 with price 70 and store3 with price 80. The product is not available in store2.

Solutions

SQL