Apache Pig - GetDay()


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

Syntax

Here is the syntax of the GetDay() function.

grunt> GetDay(datetime)

Example

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.

date.txt

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 as shown below.

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

Following is an example of the GetDay() function. The GetDay() function will retrive the day from the given Date-Time object. Therefore, first of all, let us 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;
(1989-09-26T09:00:00.000+05:30)
(1980-06-20T10:22:00.000+05:30)
(1990-12-19T03:11:44.000+05:30)

Now, let us get the day from the date-of-birth using GetDay() function and store it in the relation named getday_data.

grunt> getday_data = foreach todate_data generate(date_time), GetDay(date_time);

Verify the contents of the getday_data relation using the Dump operator.

grunt> Dump getday_data;
   
(1989-09-26T09:00:00.000+05:30,26) 
(1980-06-20T10:22:00.000+05:30,20) 
(1990-12-19T03:11:44.000+05:30,19) 
apache_pig_date_time_functions.htm
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