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POHibernate Mapping Help!
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copied!<p>I am quite new to Hibernate so I am not entirely sure if what I want to do is even possible (or the right thing to do) so if it is not, feel free to suggest other ways of achieving what I am looking for.</p> <p>I have 2 entities, Competition and Fixture. There is a One-to-Many relationship between them. I know how to set up the annotations to achieve this, but what I am struggling with is making the relationship bidirectional. If my application were to run for a long time, the number of Fixtures belonging to a competition would build up. The most common way I will be accessing the Fixture objects is via a Competition by specifying a particular date (e.g. getFixtures(today)). I thought I could implement this by having a Map in the Competition class that maps the date of the Fixture to a collection of Fixtures for that date. I have no idea how to set this up in Hibernate though.</p> <p>Here is a simplified set of POJOs and Annotations that illustrate what I have so far:</p> <pre><code>@Entity public class Competition { // This is what I would like to have. private Map<Date, Collection<Fixture>> fixtureMap; public Collection<Fixture> getFixtures(Date day) { return fixtureMap.get(day); } // This is all I know how to do. private Collection<Fixture> fixtureList; @OneToMany(mappedBy = "competition") public Collection<Fixture> getFixtureList() { return fixtureList; } } @Entity public class Fixture { private Competition competition; @ManyToOne public Competition getCompetition() { return competition; } } </code></pre> <p>As you can see from this I can set the relationship up to access the entire set of Fixtures for a competition. But to get the Fixtures for a specific day I would have to iterate over the entire collection of Fixtures and check the dates of each. Is there any way I can get Hibernate to handle the mapping from Date to a Collection of Fixtures? If I could do that then I would be able to simply access the collection of Fixtures for that day using the Date as the key in the Map.</p>

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