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What is GetWeekYear() in Apache Pig ?
- The GetWeekYear() function accepts a date-time object as a parameter and returns the current week year from the given date-time object.
Syntax:
grunt> GetWeekYear(datetime)
Example:
- Ensure that you have a file named wikitechy_date.txt in the HDFS directory /pig_data/ as shown below.
- This file contains the date-of-birth details of a particular person, id, date, and time.
wikitechy_date.txt
001,1996/10/4 03:11:44
002,1980/06/20 10:22:00
003,1989/10/16 09:00:00
- You have loaded this file into Pig with a relation named date_data as shown below.
grunt> date_data = LOAD 'hdfs://localhost:9000/pig_data/date.txt' USING PigStorage(',')
as (id:int,date:chararray);
- An example of the GetWeekYear() function.
- It will retrive the current week year from the given date-time object.
- Hence, we generate the date-time objects of all employees using todate() function as shown below.
grunt> todate_data = foreach date_data generate ToDate(date,'yyyy/MM/dd HH:mm:ss')
as (date_time:DateTime );
grunt> Dump todate_data;
(1996/10/4 03:11:44 :.000+05:30)
(1980/06/20 10:22:00:.000+05:30)
(1989/10/16 09:00:00.000+05:30)
- Let us get the month from the date-of-birth of each employee using GetWeekYear() function and store it in the relation named getweekyear_data as shown below.
grunt> getweekyear_data = foreach todate_data generate (date_time), GetWeekYear(date_time);
Verification:
- You have verify the contents of the getweekyear_data relation using the Dump operator.
grunt> Dump getweekyear_data;
Output:
(1996/10/4 03:11:44.000+05:30,1996)
(1980/06/20 10:22:00.000+05:30,1980)
(1989/10/16 09:00:00.000+05:30,1989)