如何在pig中执行此逗号分隔列表？

Question

假设数据集包含两个字段:字段、问题时间

            fields                                 question time

php,error,gd,image-processing                               1235000501
php,error,gd,image-processing                               1235000551 
lisp,scheme,subjective,clojure                              1235000177
lisp,scheme,subjective,clojure                              1235001545
lisp,scheme,subjective,clojure                              1235002457
lisp,scheme,subjective,clojure                              1235002809
lisp,scheme,subjective,clojure                              1235003266
lisp,scheme,subjective,clojure                              1235007817
lisp,scheme,subjective,clojure                              1235007913
lisp,scheme,subjective,clojure                              1235020626
lisp,scheme,subjective,clojure                              1235040652

我尝试了下面的代码

DEFINE UnixToISO org.apache.pig.piggybank.evaluation.datetime.convert.UnixToISO();
A= LOAD '/user/home/book3.csv' using PigStorage() as (fields:chararray,question time:long);
B= foreach A generate fields,UnixToISO(question time * 1000 ) as temp;
DUMP B;

没有与输入相同的更改

C= foreach B generate fields, ToDate(temp) as date_time;
DUMP C;

没有与输入相同的更改

D= foreach C generate fields, GetHour(date_time) as hour;
DUMP D;

没有相同的更改，因为input.What在我的代码中是错误的？

Answer 1

我认为示例数据的格式不符合分隔两列中数据的分隔符。我提取了示例数据，删除了列数据之间的空格，并将它们替换为一个tab.In，这样我就能够加载两列数据并提取时间戳和获取小时。参见下面的脚本和输出。

脚本

A = LOAD 'test4.txt' using PigStorage('\t') AS (fields:chararray,question_time:long);
B = foreach A generate fields,ToDate(question_time * 1000 ) as temp;
C = foreach B generate fields, GetHour(temp) as hour;
DUMP C;

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