将瞬态属性映射到别名-Spring JPA

Question

Is it possible in Spring JPA to map a Transient property of an Object to an alias like so?

Native Query

SELECT *, 1 AS liked FROM User WHERE user_id = 123 // + logic to determine if liked

Class

@Entity
public class User {

    @Id
    private Long userId;

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

    @Transient
    private int liked; // not tied to any column

}

I've tried to implement this but liked always returns 0 where it should be 1 (and null if I defined the field as an Object type)

Any help is appreciated!

Answer 1

You should use @Formula annotation for the field (see the example )

The @Formula annotation to provide an SQL snippet which Hibernate will execute when it fetches the entity from the database. The return value of the SQL snippet gets mapped to a read-only entity attribute.