Hibernate hql inner join eager fetch on one to many, fetching redundant parent objects

hibernate, java

Solution

Use distinct:

select distinct p from ProgressNote p 
inner join fetch p.patientObjectives as o 
where p.notesKey.patient.id = :patientId)

Problem

I have entities as follows Class ProgressNote ``` @Entity public class ProgressNote implements Serializable{ @Id private NotesKey notesKey = new NotesKey(); private Set<PatientObjective> patientObjectives; public NotesKey getNotesKey() { return notesKey; } public void setNotesKey(NotesKey notesKey) { this.notesKey = notesKey; } @OneToMany(fetch=FetchType.LAZY) @Access(AccessType.PROPERTY) @JoinColumns({ @JoinColumn(name="noteNumber",referencedColumnName="noteNumber"), @JoinColumn(name="ddate",referencedColumnName="ddate"), @JoinColumn(name="patient_id",referencedColumnName="patient_id") }) public Set<PatientObjective> getPatientObjectives() { return patientObjectives; } public void setPatientObjectives(Set<PatientObjective> patientObjectives) { this.patientObjectives = patientObjectives; } } ``` Class NotesKey ``` @Embeddable public class NotesKey implements Serializable{ private Byte noteNumber; @Temporal(javax.persistence.TemporalType.DATE) @Column(name="ddate") private Date noteDate; private Patient patient; public Byte getNoteNumber() { return noteNumber; } public void setNoteNumber(Byte noteNumber) { this.noteNumber = noteNumber; } public Date getNoteDate() { return noteDate; } public void setNoteDate(Date noteDate) { this.noteDate = noteDate; } @ManyToOne(fetch=FetchType.LAZY) @Access(AccessType.PROPERTY) public Patient getPatient() { return patient; } public void setPatient(Patient patient) { this.patient = patient; } @Override public int hashCode() { ........ } @Override public boolean equals(Object obj) { ........ } } ``` Class PatientObjective ``` @Entity public class PatientObjective implements Serializable{ @Id private PatientObjectiveKey patientObjectiveKey; public PatientObjectiveKey getPatientObjectiveKey() { return patientObjectiveKey; } public void setPatientObjectiveKey(PatientObjectiveKey patientObjectiveKey) { this.patientObjectiveKey = patientObjectiveKey; } } ``` Class PatientObjectiveKey ``` @Embeddable public class PatientObjectiveKey implements Serializable{ private Objective objective; private Byte noteNumber; @Temporal(javax.persistence.TemporalType.DATE) @Column(name="ddate") private Date noteDate; private Patient patient; @ManyToOne(fetch=FetchType.LAZY) @Access(AccessType.PROPERTY) public Objective getObjective() { return objective; } public void setObjective(Objective objective) { this.objective = objective; } public Byte getNoteNumber() { return noteNumber; } public void setNoteNumber(Byte noteNumber) { this.noteNumber = noteNumber; } public Date getNoteDate() { return noteDate; } public void setNoteDate(Date noteDate) { this.noteDate = noteDate; } @ManyToOne(fetch=FetchType.LAZY) @Access(AccessType.PROPERTY) public Patient getPatient() { return patient; } public void setPatient(Patient patient) { this.patient = patient; } @Override public int hashCode() { ....... } @Override public boolean equals(Object obj) { ........ } } ``` After I use this named query @NamedQuery(name = "findAllProgressNoteWithObjective", query = "from ProgressNote p inner join fetch p.patientObjectives as o where p.notesKey.patient.id = :patientId)") using spring hibernate template findByNamedQueryAndNamedParam In table I have 2 ProgressNotes with one having single Objective and other having 17 Objectives. I get the result in Java as follows. Query Generated as ``` select progressno0_.ddate as ddate46_0_, progressno0_.noteNumber as noteNumber46_0_, progressno0_.patient_id as patient17_46_0_, patientobj1_.ddate as ddate36_1_, patientobj1_.noteNumber as noteNumber36_1_, patientobj1_.objective_id as objective5_36_1_, patientobj1_.patient_id as patient6_36_1_, progressno0_.assessment as assessment46_0_, progressno0_.bloodPressure1 as bloodPre4_46_0_, progressno0_.bloodPressure2 as bloodPre5_46_0_, progressno0_.creationDate as creation6_46_0_, progressno0_.height as height46_0_, progressno0_.lastUpdatedDate as lastUpda8_46_0_, progressno0_.plans as plans46_0_, progressno0_.status as status46_0_, progressno0_.subject as subject46_0_, progressno0_.temprature as temprature46_0_, progressno0_.tempratureUnit as temprat13_46_0_, progressno0_.lastid as lastid46_0_, progressno0_.waist as waist46_0_, progressno0_.weight as weight46_0_, progressno0_.weightUnit as weightUnit46_0_, patientobj1_.remark as remark36_1_, patientobj1_.value as value36_1_, patientobj1_.ddate as ddate46_0__, patientobj1_.noteNumber as noteNumber46_0__, patientobj1_.patient_id as patient6_46_0__, patientobj1_.ddate as ddate0__, patientobj1_.noteNumber as noteNumber0__, patientobj1_.objective_id as objective5_0__, patientobj1_.patient_id as patient6_0__ from pnheader progressno0_ inner join pnobjremark patientobj1_ on progressno0_.ddate=patientobj1_.ddate and progressno0_.noteNumber=patientobj1_.noteNumber and progressno0_.patient_id=patientobj1_.patient_id where progressno0_.patient_id=? ``` Question Problem I see is why I am getting multiple single instance of ProgressNote(id=152).Is there a way I can avoid this duplication? I'll really appreciate if someone explains or points me in right direction. Using Hibernate 3.6, Mysql 5.6.10

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