CODEWITHSUNDEEP
apache-pig
Sam
Sam

Reputation: 1363

How to handle null + number addition in pig gracefully

I have a data schema where i am having 50+ cols. Now i have a scenario where i need to add four int columns together. there might be the chance that anyone out of four can be null. 

if i do  null + 1 + null + 7 i get the result as null which is true as per given in the PIG 
https://pig.apache.org/docs/r0.7.0/piglatin_ref2.html#Nulls

i.e. if either sub-expression is null, the resulting expression is null.

Could someone please let me know as how to handle as such scenarios. Do i need to define a UDF or just caring null and then perform add operation is good. Thanks in advance

Upvotes: 2

Views: 1043

Answers (1)

Sivasakthi Jayaraman
Sivasakthi Jayaraman

Reputation: 4724

One option is, if the column value is null set the column value as zero else proceed with original value. sample example below.

input.txt

1,,3
,5,6
7,8,

PigScript:

A = LOAD 'input.txt' USING PigStorage(',') AS (f1:int,f2:int,f3:int);
B = FOREACH A GENERATE ((f1 is null)?0:f1) + ((f2 is null)?0:f2) +((f3 is null)?0:f3);
DUMP B;

Output:

(4)
(11)
(15)

Upvotes: 3

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