not()

Learn how to use the not() function to reverse the value of its boolean argument.

Reverses the value of its bool argument.

Syntax

not(expr)

Parameters

NameTypeRequiredDescription
exprscalar✔️An expression that evaluates to a boolean value. The result of this expression is reversed.

Returns

Returns the reversed logical value of its bool argument.

Examples

The following query returns the number of events that are not a tornado, per state.

StormEvents 
| where not(EventType == "Tornado") 
| summarize count() by State

Output

StateCount
TEXAS4485
KANSAS3005
IOWA2286
ILLINOIS1999
MISSOURI1971
GEORGIA1927
MINNESOTA1863
WISCONSIN1829
NEBRASKA1715
NEW YORK1746
……

The following query excludes records where either the EventType is hail, or the state is Alaska.

StormEvents
| where not(EventType == "Hail" or State == "Alaska")

The next query excludes records where both the EventType is hail and the state is Alaska simultaneously.

StormEvents
| where not(EventType == "Hail" and State == "Alaska")

Combine with other conditions

You can also combine the not() function with other conditions. The following query returns all records where the EventType is not a flood and the property damage is greater than $1,000,000.

StormEvents
| where not(EventType == "Flood") and DamageProperty > 1000000