MYSQL union solution
\n# Write your MySQL query statement below\nselect * from (\nselect product_id,\'store1\' as store, store1 as price from Products\nunion \nselect product_id,\'s
```\n# Write your MySQL query statement below\nselect * from (\nselect product_id,\'store1\' as store, store1 as price from Products\nunion \nselect product_id,\'store2\' as store, store2 as price from Products\nunion\nselect product_id,\'store3\' as store, store3 as price from Products\n) store where price is not null\n```
['Union Find', 'MySQL']