LEFT JOIN
を使用してこれを行うことができます :
SELECT b.Product, b.Qty, b.Price, Result = CASE WHEN a.product IS NULL THEN 'New' ELSE 'Updated: ' + STUFF( CASE WHEN a.Qty != b.Qty THEN ',Qty' ELSE '' END + CASE WHEN a.Price != b.Price THEN ',Price' ELSE '' END, 1, 1, '') END FROM TableB b LEFT JOIN TableA a ON a.Product = b.Product WHERE a.Product IS NULL OR a.Qty != b.Qty OR a.Price != b.Price;
プレ>