Apache PIG - 仅从时间戳获取日期 [英] Apache PIG - Get only date from TimeStamp

问题描述

我有以下代码:

Data = load '/user/cloudera/' using PigStorage('\t') 
as
(   ID:chararray, 
    Time_Interval:chararray, 
    Code:chararray); 

transf = foreach Source_Data generate  (int) ID, 
                                   ToString( ToDate((long) Time_Interval), 'yyyy-MM-dd hh:ss:mm') as TimeStamp,
                        (int) Code; 

SPLIT transf INTO       Src25 IF (ToString(TimeStamp, 'yyyy-MM-dd')=='2016-07-25'),
                        Src26 IF (ToString(TimeStamp, 'yyyy-MM-dd')=='2016-07-26');


STORE Src25 INTO '/user/cloudera/2016-07-25' using PigStorage('\t');
STORE Src26 INTO '/user/cloudera/2016-07-26' using PigStorage('\t');

我想按日期和我在 Split 语句中放入的规则拆分文件，它给了我错误...

I want to split the files by date and the rules that I'm putting in Split statement it gives me error...

如何转换 Date 中的 TimeStamp(用于 transf 语句)以进行比较?

How can I transform TimeStamp (used on transf statement) in Date to make the comparasion?

非常感谢！

推荐答案

从 ToDate 获取日期时间对象后，对日期时间对象使用 GetYear(),GetMonth(),GetDay() 并使用 CONCAT 只构造日期.

After you get the datetime object from ToDate, use GetYear(),GetMonth(),GetDay() on the datetime object and use CONCAT to construct only the date.

transf = foreach Source_Data generate  
                   (int) ID, 
                   ToString( ToDate((long) Time_Interval), 'yyyy-MM-dd hh:ss:mm') as TimeStamp,
                   (int) Code;

transf_new = foreach transf generate
                     ID,
                     TimeStamp,
                     CONCAT(CONCAT(CONCAT(GetYear(TimeStamp),'-')),(CONCAT(GetMonth(TimeStamp),'-')),GetDay(TimeStamp)) AS Day,-- Note:Brackets might be slightly off but it should be like 'yyyy-MM-dd' format
                     Code;

-- Now use the new Day column to split the data
SPLIT transf_new INTO       Src25 IF (Day =='2016-07-25'),
                            Src26 IF (Day =='2016-07-26');

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