EASY_SOLUTION
SELECT Product_id, Store, Price\nFrom Products\nUNPIVOT\n(\nStore for price in (\n[store1],[store2],[store3]\n)\n) as u\n
SELECT Product_id, Store, Price\nFrom Products\nUNPIVOT\n(\nStore for price in (\n[store1],[store2],[store3]\n)\n) as u\n
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