Many-to-many relationships with a dollop of Ajax
Many-to-many (m:m) relationships can be tricky to deal with in a Web application. In this installment of Mastering Grails, Scott Davis shows you how to implement m:m relationships in Grails successfully. See how they're handled by the Grails Object Relational Mapping (GORM) API and the back-end database. Also find out how a bit of Ajax (Asynchronous JavaScript + XML) can streamline the user interface.
http://www.ibm.com/developerworks/java/library/j-grails04158