你有两个选择:

 SELECT ItemID, 
        Inventory_Name, 
        AvailableQuantity 
 FROM Inventory
 ORDER BY AvailableQuantity  ASC
 LIMIT 1;

但这不处理关系,所以可以使用子查询:

SELECT ItemID, 
        Inventory_Name, 
        AvailableQuantity 
 FROM Inventory
 WHERE AvailableQuantity in (SELECT MIN(AvailableQuantity) FROM Inventory i2);