Creating a OneToMany relationship between two objects in Spring Boot Kotlin-CodePudding

I'm struggling to wrap my head around how relationships are supposed to be set out in Spring Boot.

At the moment I have a User class (unfortunately in Java as I've not gotten around to converting it to Kotlin) and a Job class (in Kotlin).

When a Job is created, I need the user to be assigned to it. I also want to be able to see who created the job from Job.

Here's what I've tried so far:

User.java

@OneToMany(mappedBy="creationUser")
private Set<Job> createdJobs = new HashSet<>()

...

public Set<Job> getCreatedJobs() { return createdJobs; }

public void setCreatedJobs(Set<Job> createdJobs) { this.createdJobs = createdJobs; }

Job (Kotlin data class):

@Column(name = "creationUser")
val creationUser: User? = null,

I get the following error when I try and run it (still a little new to Spring Boot so not sure what it's saying)

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not determine type for: com.jre.hireout.database.entities.users.User, at table: table_jobs, for columns: [org.hibernate.mapping.Column(creation_user)]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1804) ~[spring-beans-5.3.22.jar:5.3.22]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:620) ~[spring-beans-5.3.22.jar:5.3.22]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.22.jar:5.3.22]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.22.jar:5.3.22]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.22.jar:5.3.22]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.22.jar:5.3.22]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.22.jar:5.3.22]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1154) ~[spring-context-5.3.22.jar:5.3.22]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:908) ~[spring-context-5.3.22.jar:5.3.22]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.22.jar:5.3.22]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:147) ~[spring-boot-2.7.3.jar:2.7.3]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:734) ~[spring-boot-2.7.3.jar:2.7.3]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:408) ~[spring-boot-2.7.3.jar:2.7.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:308) ~[spring-boot-2.7.3.jar:2.7.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306) ~[spring-boot-2.7.3.jar:2.7.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295) ~[spring-boot-2.7.3.jar:2.7.3]
    at com.jre.hireout.HireOutApplication.main(HireOutApplication.java:26) ~[classes/:na]
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:577) ~[na:na]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.7.3.jar:2.7.3]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not determine type for: com.jre.hireout.database.entities.users.User, at table: table_jobs, for columns: [org.hibernate.mapping.Column(creation_user)]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:421) ~[spring-orm-5.3.22.jar:5.3.22]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) ~[spring-orm-5.3.22.jar:5.3.22]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.3.22.jar:5.3.22]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1863) ~[spring-beans-5.3.22.jar:5.3.22]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1800) ~[spring-beans-5.3.22.jar:5.3.22]
    ... 19 common frames omitted
Caused by: org.hibernate.MappingException: Could not determine type for: com.jre.hireout.database.entities.users.User, at table: table_jobs, for columns: [org.hibernate.mapping.Column(creation_user)]
    at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:515) ~[hibernate-core-5.6.10.Final.jar:5.6.10.Final]
    at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:482) ~[hibernate-core-5.6.10.Final.jar:5.6.10.Final]
    at org.hibernate.mapping.Property.isValid(Property.java:231) ~[hibernate-core-5.6.10.Final.jar:5.6.10.Final]
    at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:627) ~[hibernate-core-5.6.10.Final.jar:5.6.10.Final]
    at org.hibernate.mapping.RootClass.validate(RootClass.java:267) ~[hibernate-core-5.6.10.Final.jar:5.6.10.Final]
    at org.hibernate.boot.internal.MetadataImpl.validate(MetadataImpl.java:359) ~[hibernate-core-5.6.10.Final.jar:5.6.10.Final]
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:314) ~[hibernate-core-5.6.10.Final.jar:5.6.10.Final]
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:471) ~[hibernate-core-5.6.10.Final.jar:5.6.10.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1498) ~[hibernate-core-5.6.10.Final.jar:5.6.10.Final]
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.3.22.jar:5.3.22]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.3.22.jar:5.3.22]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) ~[spring-orm-5.3.22.jar:5.3.22]
    ... 23 common frames omitted

CodePudding user response：

The way you are declaring this, you are telling Hibernate that creationUser is a basic typed field, where basic types are things like String, Integer etc.

You should instead mark this as an association and use the @JoinColumn annotation.

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "creationUser")
val creationUser: User? = null,