instances_exist

Description

instance_exists or instances_exist returns True if the case has at least one instance of the specified type(s). Like with other declarations an optional where clause is also supported.

Example: Ontology and Role

instances_exist(Person, AccountHolder)

This will return True if there is at least one Person with the role AccountHolder.

Example: Ontology and Where-Clause

instance_exists(Person where self.first_name = 'Thorben')

This will return True if there is at least one Person with the first_name Thorben.