I have a dashboard populated with a number of Kusto KQL Queries.
Sometimes, my query below returns zero results (for instance if by miracle, there are no failures in the last 24 hours).
//my dashboard query
let failureResults = exceptions | where blahblahblah;
failureResults;
When there are no items that match the filters, my dashboard is filled with
'The query returned no Results'.
How could I go about checking if this variable is null and then doing a different op? For instance, if it's null, then I would just issue a print "No Failures for today, awesome!";
instead.
I have tried iff()
statements and isempty(failures| distinct Outcome)
and the like, but to no avail. For example, here is another one which didn't work:
failures | project column_ifexists(tostring(Outcome),"No failures where reported!")
Just thought on an improved solution based on pack_all() and the bag_unpack plugin
let p_threshold = ... ;// set value
let failureResults = datatable(exception_id:int,exception_val:int,exception_text:string)[1,100,"Hello" ,2,200,"World"];
failureResults
| where exception_val > p_threshold
| as t1
| project result = pack_all()
| union kind=outer (print msg = 'No Failures for today, awesome!' | where toscalar(t1 | take 1 | count) == 0 | project result = pack_all())
| evaluate bag_unpack(result)
let p_threshold = 0;
exception_id | exception_text | exception_val |
---|---|---|
1 | Hello | 100 |
2 | World | 200 |
let p_threshold = 300;
msg |
---|
No Failures for today, awesome! |