count() (aggregation function)

Applies to: ✅ Microsoft Fabric ✅ Azure Data Explorer ✅ Azure Monitor ✅ Microsoft Sentinel

Counts the number of records per summarization group, or total if summarization is done without grouping.

Null values are ignored and don't factor into the calculation.

To only count records for which a predicate returns true, use countif().

Note

This function is used in conjunction with the summarize operator.

Syntax

count()

Returns a count of the records per summarization group, or in total if summarization is done without grouping.

This example returns a count of events in states:

StormEvents
| summarize Count=count() by State

Output

bin_at() rounds values down to a fixed-size bin, which can be used to aggregate data, such as by time unit.