Pig Help：如何添加未在架构中定义的固定字段

Question

如何添加未在架构中定义的固定字段（例如日期或月份）？我运行了以下猪脚本，为我的结果表添加了一个固定日期，并收到以下错误消息：Invalid field projection. Projected field [date] does not exist in schema。

joined_table = join A by (key1), 
                 B by (key1);

result  =  foreach joined_table generate 
                    20140625 as date,
                    A::value1 as v1,
                    B::value1 as v2;

Answer 1

这是你可能想要的：

    result = FOREACH joined_table GENERATE '20140625' as date, A::some_field;