count() (aggregation function)

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

• Can be used only in context of aggregation inside summarize
• Use the countif aggregation function to count only records for which some predicate returns true.

Syntax

count ( )

Returns

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

Example

Counting events in states starting with letter W:

StormEvents
| where State startswith "W"
| summarize Count=count() by State