! (bang sign) operator
Applies to:  Databricks SQL 
 Databricks Runtime
Returns the logical NOT of a Boolean expression. This operator is a synonym for not operator.
Syntax
!expr
Arguments
expr: ABOOLEANexpression.
Returns
A BOOLEAN.
Examples
SQL
> SELECT !true;
 false
> SELECT !false;
 true
> SELECT !NULL;
 NULL