Apache Pig - AddDuration()


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This function accepts a date-time object and a duration objects, and adds the given duration to the date-time object and returns a new date-time object with added duration.

Syntax

Here is the syntax of the AddDuration() function.

grunt> AddDuration(datetime, duration)

Note − The Duration is represented in ISO 8601 standard. According to ISO 8601 standard P is placed at the beginning, while representing the duration and it is called as duration designator. Likewise,

  • Y is the year designator. We use this after declaring the year.

    Example − P1Y represents 1 year.

  • M is the month designator. We use this after declaring the month.

    Example − P1M represents 1 month.

  • W is the week designator. We use this after declaring the week.

    Example − P1W represents 1 week.

  • D is the day designator. We use this after declaring the day.

    Example − P1D represents 1 day.

  • T is the time designator. We use this before declaring the time.

    Example − PT5H represents 5 hours.

  • H is the hour designator. We use this after declaring the hour.

    Example − PT1H represents 1 hour.

  • M is the minute designator. We use this after declaring the minute.

    Example − PT1M represents 1 minute.

  • S is the second designator. We use this after declaring the second.

    Example − PT1S represents 1 second.

Example

Assume that there is a file named date.txt in the HDFS directory /pig_data/. This file contains the date-of-birth details of a particular person, id, date and time and some duration according to ISO 8601 standard.

date.txt

001,1989/09/26 09:00:00,PT1M
002,1980/06/20 10:22:00,P1Y
003,1990/12/19 03:11:44,P3M 

And, we have loaded this file into Pig with a relation named date_duration as shown below.

grunt> date_duration = LOAD 'hdfs://localhost:9000/pig_data/date.txt' USING PigStorage(',')
   as (id:int, date:chararray, duration:chararray)

Following is an example of the AddDuration() function. You can add certain Duration to the given date-time object using this method as shown below.

grunt> Add_duration_data = foreach date_duration generate(date,duration), 
   AddDuration(ToDate(date,'yyyy/MM/dd HH:mm:ss'), duration);

The result of the statement will be stored in the relation named add_duration_data. Verify the content of this relation using the Dump operator as shown below.

grunt> Dump add_duration_data;
  
((1989/09/26 09:00:00,PT1M),1989-09-26 T09:01:00.000+05:30)
((1980/06/20 10:22:00,P1Y),1981-06-20 T10:22:00.000+05:30)
((1990/12/19 03:11:44,P3M),1991-03-19 T03:11:44.000+05:30)
apache_pig_date_time_functions.htm
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