Splunk Search

Any difference between NULL and null() in eval?

helge
Builder

In an eval expression, is there any difference between using NULL and null()?

Use case: I want to return null in an eval expression. I am finding that the following two expressions give the same result and I want to make sure that both are officially correct:

  • if (isnotnull (fieldX), fieldX * 10, NULL)
  • if (isnotnull (fieldX), fieldX * 10, null())
1 Solution

woodcock
Esteemed Legend

In the former case, you are setting it to the value of the field named NULL, which in your case, clearly doesn't exist right now HOWEVER that might not always be the case. It is equivalent to if(isnotnull(fieldX), fieldX*10, ThisFieldNameDoesNotExistSoTheValueThatItHasAlsoDoesNotExistSoRightNowThisEvaluatesToNULL). So it is very poor practice to use the former and you should use the latter.

View solution in original post

woodcock
Esteemed Legend

In the former case, you are setting it to the value of the field named NULL, which in your case, clearly doesn't exist right now HOWEVER that might not always be the case. It is equivalent to if(isnotnull(fieldX), fieldX*10, ThisFieldNameDoesNotExistSoTheValueThatItHasAlsoDoesNotExistSoRightNowThisEvaluatesToNULL). So it is very poor practice to use the former and you should use the latter.

helge
Builder

Now you mention it the answer is quite obvious 😉
Thanks!

0 Karma

DalJeanis
Legend

Ah yes, The Field Who Must Not Be Named...

Get Updates on the Splunk Community!

Unlock Database Monitoring with Splunk Observability Cloud

  In today’s fast-paced digital landscape, even minor database slowdowns can disrupt user experiences and ...

Purpose in Action: How Splunk Is Helping Power an Inclusive Future for All

At Cisco, purpose isn’t a tagline—it’s a commitment. Cisco’s FY25 Purpose Report outlines how the company is ...

[Upcoming Webinar] Demo Day: Transforming IT Operations with Splunk

Join us for a live Demo Day at the Cisco Store on January 21st 10:00am - 11:00am PST In the fast-paced world ...