Checks that the value provided in a field exists as the primary key of another table.
Checks that a list of fields from an entity are unique in the table
© 2005–2016 The Cake Software Foundation, Inc.
Licensed under the MIT License.
CakePHP is a registered trademark of Cake Software Foundation, Inc.
We are not endorsed by or affiliated with CakePHP.
http://api.cakephp.org/3.1/namespace-Cake.ORM.Rule.html