Hibernate One-To-One: Getid() Without Fetching Entire Object

Hibernate one-to-one: getId() without fetching entire object

Use property access strategy

Instead of

@OneToOne(fetch=FetchType.LAZY, optional=false)
private Bar bar;

Use

private Bar bar;

@OneToOne(fetch=FetchType.LAZY, optional=false)
public Bar getBar() {
    return this.bar;
}

Now it works fine!

A proxy is initialized if you call any method that is not the identifier getter method. But it just works when using property access strategy. Keep it in mind.

See: Hibernate 5.2 user guide

Hibernate: One to Many getId() not to fetch compete object

It is possible, of course. You can use FetchType.LAZY and get an id by this way:

LazyInitializer initializer = ((HibernateProxy) many.getOne()).getHibernateLazyInitializer();
Long id = (Long) initializer.getIdentifier();

It will work only with foreign key associations, not with join table associations.

Or you can use HQL or criteria with a projection, to get an only id.

Hibernate, get foreign id without loading associated entity

I think you will have have to change your Country entity like below.Add AccessType annotation on the Id field.

@Entity
    public class Country {
        @Id@GeneratedValue@AccessType("property")
        private Integer id;

        private String name;

Faced similar problem,and followed this article:-
Accessor Type Annotation

Just getting id column value not using join in hibernate object one to many relation

Yes, because proxies contain the id anyway. To get the id of an A proxy without initializing it, first declare the id to be accessed via property:

@Entity
public class A {
  @Id
  @Access(AccessType.PROPERTY)
  private int id;

  @OneToMany(fetch=LAZY)
  private List<B> list;

  public int getId() {
    return id;
  }

  public void setId(int id) {
    this.id = id;
  }
}

Then, just read the id:

b.getA().getId();

Changing access type for the id is necessary because if you use field access, Hibernate does not distinguish getId() method from other ordinary methods (which trigger proxy initialization when invoked).

JPA get foreign key without loading related record

Try mapping the FOO_ID column as a basic mapping instead or in addition to the existing Foo reference mapping:

@Entity
@Table(name="bar")
public class Bar
{
    @Id
    @Type(type = "pg-uuid")
    private UUID id;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name="FOO_ID")
    private Foo foo;

    @Column(name="FOO_ID", insertable=false, updatable=false)
    private UUID fooId;
...

    public UUID getFooId(){
        return fooId;
    }

You can then decide to use fooId in queries to avoid joins. Because it is read-only, the FK value is still set from the foo reference - there may be some issues with a cache if you set the reference and not the fooId UUID; you can either set it yourself, or force a refresh to have JPA do it for you.

Get ID for a lazy many-to-one object with NO db access

Just do it! Hibernate is smart enough to not deep-load objects unless you need their other properties, so calling A.getB().getId() shouldn't result in the deep-loading of B (it'll use the id of B stored in A).

Here's a website that explains the concept in a bit more detail: Getting the Id from Lazy Loaded Object Using Annotations in Hibernate

Try it out and see for yourself.

Is there a way to disable fetching the entire value set for a column in Hibernate?

If these "obsolete" records no longer fit into your Hibernate data model, then I recommend just moving them to some archive table. After all, you can't really select them now anyway using Hibernate, so at least at the application level, they serve no purpose.

For a more general way to logically delete a record without physically removing it, look into soft deletion. Using soft deletion, you would add a single boolean column to the table which, if marked, would indicate that the record is logically no longer there.

Hibernate/JPA - how to get id of a @ManyToOne field without triggering lazy load

For these purposes I do map the column twice. Once as many-to-one with insert="true" and update="true".

then I append an TeamId property and mapp it as int insert="false" and update="false". Instead of column mapping I use formula.

TeamId is then available after the first select.

JPA + Hibernate - How to get FK of child entity without fetching that entity?

OK, after reading following article http://256stuff.com/gray/docs/misc/hibernate_lazy_field_access_annotations.shtml
I have realized, that property access should be to the property I want to fetch, not the actual child object. So changing id access of AbstractEntityfrom field to property, makes the trick.

LazyInitializationException on getId() of a @ManyToOne reference

When field access is used, Hibernate treats getId() method the same as any other method, meaning that calling it triggers proxy initialization, thus leading to LazyInitializationException if invoked on a detached instance.

To use property access only for id property (while keeping field access for all the other properties), specify AccessType.PROPERTY for the id field:

@Entity
public class A {
  @Id
  @Access(AccessType.PROPERTY)
  private int id;

  public int getId() {
    return id;
  }

  public void setId(int id) {
    this.id = id;
  }
}

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