Is there any Conditional IF like operator in Apache PIG?

Question

Actually I am writing PIG Script and want to execute some set of statements if one of the condition is satisfied.

I have set one variable and checking for some value of that variable. Suppose

if flag==0 then
  A = LOAD 'file' using PigStorage() as (f1:int, ....);
  B = ...;
  C = ....;
else 
  again some Pig Latin statements

Can I do this in PIG Script? If yes, then how can I do this?

Thanks.

I came across conditional operator in Pig Latin like (a == b ? c1 : c2);. But How can I insert bulk of Pig Statements in between that? — Bhavesh Shah
Bhavesh, You need to write a wrapper for that The recommended approach for writing programs that have conditional logic or loop constructs is to embed Pig Latin in another language like Python, JavaScript or Java, and manage the control flow from there. — Nag

Will High Will High · Accepted Answer · 2013-09-30T17:10:28

Yes, Pig does offer an if-then-else construction, but it is not used in the way you're asking.

Pig's if-then-else is an arithmetic operator invoked with the shorthand "condition ? true_value : false_value" as part of an expression, such as:

X = FOREACH A GENERATE f2, (f2==1?1:COUNT(B));

You have to already have loaded the table A to do this. To execute control flow around entire Pig statements you'll need something like oozie, as suggested by Fakrudeen.

Is there any Conditional IF like operator in Apache PIG?

5 Answers