How to merge two strings when both of them are not null

I just started exploring Druid and I’ve managed to set up a successful ingestion from my Kafka. However I ran into a problem that I couldn’t figure out how to solve. So I thought I’d ask here.

The solution is probably really simple but I couldn’t find anything helpful in the documentation.

In my data I have two fields width and height, and I’d like to concat them to get a resolution field. However the fields are sometimes null so a simple concat threw and error in the GUI. I tried doing this:

if(deviceInfo.width != null && deviceInfo.height != null, concat(deviceInfo.width, “x”, deviceInfo.height), “unknown”)

But that also returned an error. So probably my syntax is incorrect but I couldn’t find anything on how to properly syntax the druid expression.

Thankful for any help figuring this out!

What are the errors you are referring to? Can you send the whole query?

Also, this (if you are using SQL):

I had another look at it and clearly I had confused how to reference strings and columns.
I was attempting to do this in the Load Data part of the GUI (under transform). I turned out that the correct expression I needed was
concat(“deviceInfo.width”,‘x’, “deviceInfo.height”)
and that it won’t concat null fields.
The error I was getting when trying to use the expression I got above was “Error: undefined” and nothing else so didn’t get much insight from that.

Best regards,

Small typo, the phrase "The error I was getting when trying to use the expression I got above " was referring to the expression I wrote in my first mail, and not the the mail I just wrote, that one worked fine! :slight_smile: