isempty()

Returns true if the argument is an empty string or is null.

isempty("") == true

Syntax

isempty([value])

Returns

Indicates whether the argument is an empty string or isnull.

x isempty(x)
"" true
"x" false
parsejson("") true
parsejson("[]") false
parsejson("{}") false

Example

T
| where isempty(fieldName)
| count