Creating a one-to-many (or many-to-many)relationship between entities

In the previous recipe, we saw how the many-to-one (or one-to-one) relationship is established between entities using the field reference command. In this recipe, we'll extend the same example to show how a one-to-many (or many-to-many) relationship can be created using the field set command. The following class diagram shows a one-to-many relationship between the FlightDescription and Flight entities:

In the given figure, you'll notice that we have added a flights field of type Set<Flight> to the FieldDescription entity, reflecting the one-to-many relationship between the FlightDescription and the Flight entity.

Getting ready

Exit the Roo shell and delete the contents of the C:\roo-cookbook\ch03-recipes directory.

Start the Roo shell from the C:\roo-cookbook\ch03-recipes directory.

Execute the ch03_relationship_many_to_one.roo script, which creates the flight-app Roo project, sets up Hibernate as a persistence provider...