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POHibernate Joined Subclasses with One to Many mapping
 

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    <p>How would you implement a model where an abstract superclass A has 2 subclasses, B and C. B has a bidirectional one-to-many relation with another class X.</p> <p>I am using the joined subclass mapping without discriminator and with anotaions (no xml). It works almost perfectly but the id from B is null in the X class. Can the X class get the id from the superclass? Or is it searching for an id in B.</p> <p>Superclass A</p> <pre><code>import javax.persistence.*; import org.hibernate.annotations.Cascade; @Entity @Table(name="t_trip") @Inheritance(strategy=InheritanceType.JOINED) public abstract class Trip { @Id @GeneratedValue(strategy= GenerationType.IDENTITY) private int id; private String name; private boolean publicTrip; private String description; public Trip(){ } public Trip(String name, String description, boolean publicTrip) { this.name = name; this.description = description; this.publicTrip = publicTrip; } } </code></pre> <p>Subclass B</p> <pre><code>import java.util.ArrayList; import java.util.Date; import java.util.List; import javax.persistence.*; import org.hibernate.annotations.Cascade; @Entity @Table(name = "t_repeatedtrip") @PrimaryKeyJoinColumn(name = "id") public class RepeatedTrip extends Trip { private Date startMoment; private String intervalType; private int tripInterval; private int tripFrequency; @OneToMany(mappedBy = "repeatedTrip") @Cascade({org.hibernate.annotations.CascadeType.SAVE_UPDATE}) private List&lt;TripExecutionMoment&gt; tripExecutionMoments = new ArrayList&lt;TripExecutionMoment&gt;(); public RepeatedTrip() { } public RepeatedTrip(String name, String description,boolean publicTrip, Date startMoment, String intervalType, int interval, int frequency) { super(name, description, publicTrip); this.startMoment = startMoment; this.intervalType = intervalType; this.tripInterval = interval; this.tripFrequency = frequency; } } </code></pre> <p>OneToMany related class X</p> <pre><code>package be.kdg.teamB.model.entities; import java.util.Date; import javax.persistence.*; import org.hibernate.annotations.Cascade; @Entity @Table(name = "t_tripexecutionmoment") public class TripExecutionMoment { @Id @GeneratedValue private int id; private Date executionPointOfTime; @ManyToOne @Cascade({org.hibernate.annotations.CascadeType.SAVE_UPDATE}) @JoinColumn(name = "repeatedTripId") private RepeatedTrip repeatedTrip; public TripExecutionMoment() { } public TripExecutionMoment(Date executionPointOfTime) { this.executionPointOfTime = executionPointOfTime; } return executionPointOfTime; } public void setExecutionPointOfTime(Date executionPointOfTime) { this.executionPointOfTime = executionPointOfTime; } public RepeatedTrip getRepeatedTrip() { return repeatedTrip; } public void setRepeatedTrip(RepeatedTrip repeatedTrip) { this.repeatedTrip = repeatedTrip; } } </code></pre> <p>Code is called in this method: </p> <pre><code>public RepeatedTrip createRepeatedTrip(String name, String description,boolean publicTrip, Date startMoment, String intervalType, int interval, int frequency) { session = HibernateUtil.getSessionFactory().getCurrentSession(); tx = session.beginTransaction(); RepeatedTrip trip = new RepeatedTrip(name, description,publicTrip, startMoment, intervalType, interval, frequency); int intervalDefiner; Date date = trip.getStartMoment(); switch(intervalType){ case "D": intervalDefiner = Calendar.DATE; break; case "M": intervalDefiner = Calendar.MONTH; break; case "W": intervalDefiner = Calendar.WEEK_OF_YEAR; break; case "Y": intervalDefiner = Calendar.YEAR; break; default: intervalDefiner = Calendar.DATE; break; } for(int i=0; i&lt;frequency;i++){ TripExecutionMoment tripExecutionMoment = new TripExecutionMoment(date); trip.getTripExecutionMoments().add(tripExecutionMoment); date = nextDate(intervalDefiner, interval, date); } session.saveOrUpdate(trip); tx.commit(); return trip; } </code></pre>
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    1. COShow us your code. You probably just forgot to initialize The `X.b` field.
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    2. COthanks for your reply. I added my code (without setters and getters, which I have for all fields). How should I initialize X.b? I do not completely understand what you mean by that.
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    3. COBut you don't show the most interesting part. Show us the code that you use to create a TripExecutionMoment and add it to a RepeatedTrip.
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