架构中不存在APACHE PIG - error Projected字段[Units_Sold]：group:chararray，D2:bag{:tuple(Item_Type:chararray，Units_Sold:int)}

Question

下午好-我有一个销售数据集，正在尝试查看哪个项目的销售量最多。下面是我的代码：

        Country:chararray,
        Item_Type:chararray,
        Sales_Channel:chararray,
        Order_Priority_site:chararray,
        Order_Date:chararray,
        Order_ID:chararray,
        Ship_Date:chararray,
        Units_Sold:int,
        Unit_Price: int,
        Unit_Cost: int,
        Total_Revenue: int,
        Total_Cost: int,
        Total_Profit:int);

D2 = FOREACH data GENERATE Item_Type, Units_Sold;

D3 = GROUP D2 BY Item_Type;

D4 = FOREACH D3 GENERATE group, SUM(Units_Sold);

DUMP D4;```

However, I get the error: 

```<file D, line 20, column 36> Invalid field projection. Projected field [Units_Sold] does not exist in schema: group:chararray,D2:bag{:tuple(Item_Type:chararray,Units_Sold:int)}.```

有人知道怎么解决这个问题吗？如果您需要更多信息，请告诉我，这是我在这里发布的第一个问题

Answer 1

萨姆在等一个袋子。该错误向您显示模式：

D2:bag{:tuple(Item_Type:chararray,Units_Sold:int)}

因此，将SUM更改为：

SUM(D2.Units_Sold)