过滤延迟初始化集合

Question

My objects: user and credential - many to many relationship, however user has a param

I want to get all users with certain param for every credential in a loop

requirement: users have to be loaded in batch.

• simple right?

so i have 3 tables:

@Table(name = "CRED")
public class Credential {

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE)
    @Column(name="CRED_ID")     
    Long credentialId;

    @OneToMany(fetch=FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "credential")
    @BatchSize(size = Search.DEFAULT_PAGE_SIZE)
    private Set<UserCredentialMapping> userCredentialMappingSet;  
}

@Table(name = "USER_CRED")
public class UserCredentialMapping {

    @JoinColumn(name = "user_id", referencedColumnName = "user_id")
    @ManyToOne
    @Filter(name="paramFilter", condition="param = :param")
    private User user;

    @JoinColumn(name = "cred_id", referencedColumnName = "cred_id")
    @ManyToOne
    private Credential credential;
}

@Table(name = "USER")
public class User  {

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE)
    @Column(name="USER_ID")     
    Long userId;

    @Column(name = "PARAM")
    String param
}

i'm making a query in one place and return results:

    String hqlQuery =   "select c from UserCredentialMapping m " +
        " inner join m.credential c" +
        " inner join m.user u" +
        " where u.param = :param" +
        " and c.user_id in (:users)" ;

        Session session = getSession();
        //desparetly trying to set filter
        session.enableFilter("paramFilter").setParameter("param", param);

    Query query = session.createQuery(hqlQuery);
    query.setParameterList("users", USERLIST);
    query.setParameter("param", someparam);

    List<Credential> credentialList = (List<Credential>)query.list();
    return credentialList;

some processing on each credential in mean time and now i need to get list of users with given param:

    for(Credential credential : credentialList){

        //following line makes hibernate query for users
        Iterator<CredentialMapping> mappingIterator = e.getUserCredentialMappingSet().iterator();

        while (mappingIterator.hasNext()){
            UserCredentialMapping userCred = mappingIterator.next();

            User user = userCred.getUser(); 
            DOEVILSTUFFTOINNOCENT(user);
    }

My problem is that iterator generates SQL query that gets all users for credential and not all users with specified param for credential (in other words filter is not being applied)

Any advise how to make it work?

Thanks !

Answer 1

I've solved it by adding ManyToMany mapping to Credential class:

@ManyToMany(fetch = FetchType.LAZY)
@NotFound(action = NotFoundAction.IGNORE)
@JoinTable(name = "USER_CRED", 
    joinColumns = { 
        @JoinColumn(name = "CRED_ID") }, 
    inverseJoinColumns = { 
        @JoinColumn(name = "USER_ID") })
@Filter(name="param", condition="PARAM = :param")
@BatchSize(size = Search.DEFAULT_PAGE_SIZE)
private Set<User> users;

i couldn't get it working through UserCredentialMapping...