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...

Got questions? Get answers!

Join the Splunk Community Slack to learn, troubleshoot, and make connections with fellow Splunk practitioners in real time!

Meet up IRL or virtually!

Join Splunk User Groups to connect and learn in-person by region or remotely by topic or industry.

Get Updates on the Splunk Community!

Deep insights, no barriers: Splunk Observability Cloud Free Edition

As software delivery cycles continue to accelerate, observability shouldn’t be a luxury — it should be a ...

Monitoring AI Agents with Splunk Observability Cloud

Let’s say I’m running a travel planning AI app in production. A user asks for three concise hotel options in ...

[Puzzles] Solve, Learn, Repeat: Tiling

This puzzle (first published here) is based on finding groups of tessellated tiles (inspired by floor tiles I ...