Hibernate Criterion in OneToMany relationship

Question

I am trying to figure out how to use hibernate criterion to get a specific set of child elements when I retrieve the parent. I have created the following example entities:

Parent Class

@Entity
public class Parent {
    @Id
    @Column(name="PARENT_ID")
    private long parentId;

    @Column(name="NAME")
    private String name;

    @OneToMany(mappedBy="parent")
    private Set<Child> children
}

Child Class

@Entity
public class Child {
    @Id
    @Column(name="CHILD_ID")
    private long childId

    @ManyToOne
    @JoinColumn(name="PARENT_ID")
    private Parent parent;

    @ManyToOne
    @JoinColumn(name="GENDER_ID")
    private Gender gender;
}

Gender Class

@Entity
public class Gender {
    @Id
    @Column(name="GENDER_ID")
    private long genderId;

    @Column(name="GENDER_IND")
    private String genderInd;
}

Hibernate Criteria

getSession()
    .createCriteria(Parent.class)
    .createAlias("children", "c")
    .createAlias("c.gender", "g")
    .add(Restrictions.eq("g.genderInd", "M"))
    .list()

This criteria gives me a list of Parents that have a male ("M") child, and it returns all of the children for each of those parents. How can I get a list of Parents that have a male child and only have the male children in the Parent.children set?

Answer 1

I searched days for the solution, i had the same problems, i have an object with a collection of traductions, and i wanted to query an object with the only current language.

I found this solution : https://docs.jboss.org/hibernate/orm/3.6/reference/en-US/html/filters.html

working for me, here a solution for you :

@Entity
public class Parent {
    @Id
    @Column(name="PARENT_ID")
    private long parentId;

    @Column(name="NAME")
    private String name;

    @OneToMany(mappedBy="parent")
    @Filter(name="gender", condition="gender.genderInd=:gender")
    private Set<Child> children
}

@Entity
@FilterDef(name="genderFilter", parameters=@ParamDef( name="gender", type="string" ) )
public class Child {
    @Id
    @Column(name="CHILD_ID")
    private long childId

    @ManyToOne
    @JoinColumn(name="PARENT_ID")
    private Parent parent;

    @ManyToOne
    @JoinColumn(name="GENDER_ID")
    private Gender gender;
}

And before you do your query :

Session session = sessionFactory.getCurrentSession();
session.enableFilter("genderFilter").setParameter("gender", "M");

Answer 2

Criteria cr = getSession()
            .createCriteria(Parent.class)
            .createAlias("children", "c")
            .createAlias("c.gender", "g");

Criterion Malechild = Restrictions.eq("g.genderInd", "M");

Criterion NFemaleChild = Restrictions.ne("g.genderInd", "F");

LogicalExpression andExp = Restrictions.and(Malechild, NFemaleChild);

cr.add(andExp);

List results = cr.list();