Apache Pig - GetMonth()


This function accepts a date-time object as a parameter and returns the current month of the current year from the given date-time object.


Here is the syntax of the GetMonth() function.

grunt> GetMonth(datetime)


Assume that there is a file named 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.


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

And, we have loaded this file into Pig with a relation named date_data.

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

Following is an example of the GetMonth() function. It will retrive the current month from the given date-time object. Therefore, First of all let’s 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;

Let us now get the month from the date-of-birth of each employee using GetMonth() function and store it in the relation named getmonth_data.

grunt> getmonth_data = foreach todate_data generate (date_time), GetMonth(date_time);

Now verify the contents of the getmonth_data relation using Dump operator as shown below.

grunt> Dump getmonth_data;