Why does "summarize count()" on a stored query result always give 0?

Question

The following creates a stored query result named "tmp" with 100 rows from StormEvents:

Run query

.set stored_query_result tmp with (previewCount = 1, expiresAfter = 1h) <| StormEvents | take 100

As expected, the following returns 100:

Run query

stored_query_result("tmp") | count

Count
100

Also as expected, this returns two rows that add up to 100:

Run query

stored_query_result("tmp")
| summarize count() by _HasDirectInjuries = InjuriesDirect > 0

_HasDirectInjuries	count_
False	98
True	2

But unexpectedly, this always returns 0:

Run query

stored_query_result("tmp") | summarize count()

count_
0

Why doesn't summarize count() work on an stored query result, when count and summarize count() by ... seem to work normally?

Answer 1

This appears to be a bug related to stored query results, we are fixing it. Thank you very much for reporting it!