CODEWITHSUNDEEP
javahibernatelazy-loading
SooCheng Koh
SooCheng Koh

Reputation: 2312

Hibernate eager/lazy load with constraint

ClassA {

 @Id
 @GeneratedValue
 @Column(name = "a_id")
 private long id;

 @OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "classA")
 private Set<ClassB> classBs;

}

ClassB {

 @ManyToOne(fetch = FetchType.LAZY)
 @JoinColumn(name = "a_id")
 private ClassA classA;

 @JoinColumn(name = "size")
 private int size;

}

How can I add constraint to ClassA's classBs when eager/lazy load it?

For example, I only want to load ClassB where size > 10 into ClassA's Set classBs.

I know that I can order the Set by using annotation @OrderBy(value = "size ASC"), but can I add constraints other than Order?

Can I achieve it using Hibernate?

I am able to do it in Laravel(a PHP framework). Eager Load Constraints in http://laravel.com/docs/eloquent#eager-loading.

Upvotes: 1

Views: 481

Answers (2)

Ean V
Ean V

Reputation: 5429

Have a look at Hibernate Filters:
Documentation
Sample
There is one thing that you should notice and that is the filters are not applied to the entity permanently and you need to enable them whenever you would like to use them:

session.enableFilter("myFilter");

Upvotes: 1

Wundwin Born
Wundwin Born

Reputation: 3475

Look into Filter and FilterDef, here is documentation

  • At classB side define FilterDef with condition
  • At classA's relationship, use Filter with name referred to filter defined at classB side.

Look this answer for example.

Upvotes: 0

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