CODEWITHSUNDEEP
javahibernatejpainheritanceorm
Marc
Marc

Reputation: 7022

Get a list of discriminator values in a JPA and Hibernate inheritance tree

Is there a utility in Hibernate to quickly get a list of discriminator values that exist within an inheritance tree? It would be useful to avoid hard-coding this in certain SQL queries.

Upvotes: 1

Views: 971

Answers (1)

Vlad Mihalcea
Vlad Mihalcea

Reputation: 153810

You can map the discriminator column to one property of your inheritance model base class:

@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "discriminator", discriminatorType = DiscriminatorType.STRING, length = 255)
public class BaseEntity { 

    @Column(name = "discriminator", insertable = false, updatable = false)
    private String discriminator;

}

Update

In HQL queries you can also use the class directive:

select e.class, e.id from YourEntity e

For SQL queries you can only use the predefined discriminator column. There's no utility to help you with that. Hibernate utilities are target towards entity queries (HQL or Criteria).

Upvotes: 2

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