isnull()
Evaluates its sole argument and returns a bool value indicating if the argument evaluates to a null value.
Note
String values can't be null. Use isempty to determine if a value of type string is empty or not.
Syntax
isnull(Expr)
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
| value | scalar | ✓ | The value to check if not null. |
Returns
true if value is not null and false otherwise.
| x | isnull(x) |
|---|---|
"" |
false |
"x" |
false |
parse_json("") |
true |
parse_json("[]") |
false |
parse_json("{}") |
false |
Example
Find the storm events for which there's not a begin location.
StormEvents
| where isnull(BeginLat) and isnull(BeginLon)