Handling an empty datatable

Elastic Stack Kibana
1

In Canvas, i’m Using the expression editor to calculate a percentage for use in a Metric object. After creating the datatable using ply, I’m executing the line:

math “mean(percentage)”

However, if my datatable is empty, this throws an exception. Is there a way in the expression editor to check for an empty datatable and only call the math fn if the datatable is NOT empty, otherwise set the metric value to 0?

2

Finally figured this one out. I replaced the line:

math "mean(percentage)"

with:

if {rowCount | eq 0} then=0 else={math "mean(percentage)"}

If the datatable is not empty, then it returns the average of the "percentage" column, otherwise it returns an "average" value of 0. Now I no longer get the error triangle at runtime of the canvas.

3 Likes
3

Thank you for posting your solution - helps others in community as well.

Thanks
Rashmi

4

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