Embeddable Not Working When column is expected to be a FK and PK at the same time

Question

I am trying to learn JPA, I'm currently encountering issues with the embeddable keywords.

My Goal is on Medical History , I would want to make firstName and lastName as Primary Key and Foreign Key however I am encountering an error message.

This is the error message that I am encountering.

Caused by: org.hibernate.AnnotationException: Unable to find column reference in the @MapsId mapping: first_name
    at org.hibernate.cfg.CopyIdentifierComponentSecondPass.createSimpleProperty(CopyIdentifierComponentSecondPass.java:203) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final]
    at org.hibernate.cfg.CopyIdentifierComponentSecondPass.doSecondPass(CopyIdentifierComponentSecondPass.java:112) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final]
    at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processFkSecondPassesInOrder(InFlightMetadataCollectorImpl.java:1691) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final]
    at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses(InFlightMetadataCollectorImpl.java:1623) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final]
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:295) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1460) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1494) ~[hibernate-core-5.6.4.Final.jar:5.6.4.Final]
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.3.15.jar:5.3.15]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.3.15.jar:5.3.15]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) ~[spring-orm-5.3.15.jar:5.3.15]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) ~[spring-orm-5.3.15.jar:5.3.15]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.3.15.jar:5.3.15]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1863) ~[spring-beans-5.3.15.jar:5.3.15]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1800) ~[spring-beans-5.3.15.jar:5.3.15]
    ... 16 common frames omitted

This is the sample code that i am trying to make work.

    @Embeddable
    public class PersonId implements Serializable {
        String firstName;
        String lastName;
    }
    
    @Entity
    public class Person implements Serializable {
        @EmbeddedId
        PersonId personId;
    }
    
    @Entity
    public class MedicalHistory implements Serializable {
        @EmbeddedId PersonId id;
    
        @MapsId
        @JoinColumns({
                @JoinColumn(name = "firstName", referencedColumnName = "firstName"),
                @JoinColumn(name = "lastName", referencedColumnName = "lastName")
        })
        @OneToOne
        Person patient;
    }

not sure what I am doing wrong?

• note: I am using this learning material "JSR 338: JavaTM Persistence API, Version 2.2"

Answer 1

@chris is absolutley right, Hibernate is turning the column name fron 'firstName' to 'first_name' and i guess it will be the same for 'lastName'.

You can also change the column names to match the naming like

  @Column(name = "first_name")
  private String firstName;

On the @Embeddable and adapt the name on the @JoinColumn that should do the trick.

If you dont generate your database schema automaticly, you will have to rename also the columns in the database.