This function is used to convert all the characters in a string to lowercase.
Following is the syntax of the LOWER() function.
Assume that there is a file named emp.txt in the HDFS directory /pig_data/ as shown below. This file contains the employee details such as id, name, age, and city.
001,Robin,22,newyork 002,BOB,23,Kolkata 003,Maya,23,Tokyo 004,Sara,25,London 005,David,23,Bhuwaneshwar 006,Maggy,22,Chennai 007,Robert,22,newyork 008,Syam,23,Kolkata 009,Mary,25,Tokyo 010,Saran,25,London 011,Stacy,25,Bhuwaneshwar 012,Kelly,22,Chennai
And, we have loaded this file into Pig with a relation named emp_data as shown below.
grunt> emp_data = LOAD 'hdfs://localhost:9000/pig_data/emp.txt' USING PigStorage(',') as (id:int, name:chararray, age:int, city:chararray);
Given below is an example of the LOWER() function. In this example, we have converted the names of all the employees to lowercase.
grunt> lower_data = FOREACH emp_data GENERATE (id,name), LOWER(name);
The above statement converts the names of all the employees to lowercase and returns the result.
The result of the statement will be stored in the relation named lower_data. Verify the content of the relation lower_data, using the Dump operator.
grunt> Dump lower_data; ((1,Robin),robin) ((2,BOB),bob) ((3,Maya),maya) ((4,Sara),sara) ((5,David),david) ((6,Maggy),maggy) ((7,Robert),robert) ((8,Syam),syam) ((9,Mary),mary) ((10,Saran),saran) ((11,Stacy),stacy) ((12,Kelly),kelly)