I’m trying to create a system to help manage company I’m in. One of the module is ticketing problems. Previously I was using nonSQL DB but decided to learn something new. I’m not sure if it’s a problem with classes or just wrong sql model. I want users to be able to create Tickets and be able to Comment them. But all I got is errors.
I have:
User.java

@Entity
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id; // identyfikator
    
    @Column(nullable = false)
    private String firstName; 
    @Column(nullable = false)
    private String lastName; 
    @Column(nullable = false)
    private String jobPosition; 
    @Column(nullable = false)
    private String department; 
    @Column(nullable = false)  
    private String shortDep; 
    @Column(nullable = false)
    private String email; 
    @Column(nullable = true)
    private String deskNumber; 
    @Column(nullable = true)
    private String mobileNumber; 
    @Column(nullable = true)
    private boolean isPrivate; 
    @Column(nullable = false)
    private String password; 
    @ManyToOne
    @JsonManagedReference
    private List<Comment> comments;
    @JsonIgnore
    private Session session;
...
}

Ticket.java

@Entity
public class Ticket {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @ManyToOne
    private User owner;
    @Column
    private DateTime postedTime;
    @Column
    private String text;
    @ManyToOne
    private User assignedUser;
    @ManyToOne
    @JsonManagedReference
    private List<Comment> comments;
...
}

Comment.java

@Entity
public class Comment {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

    @ManyToOne
    @JsonManagedReference
    private User owner;
    
    @OneToMany
    @JoinColumn(name = "ticketId")
    private Ticket ticket;
    
    @Column
    private String text;

...
}

Session.java

@Entity
public class Session {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @OneToOne
    @JsonManagedReference
    private User user;
    @Column
    private DateTime expTime;
}

Error I got:

ERROR 1 --- [ticket_sys_backend] [           main] j.LocalContainerEntityManagerFactoryBean : Failed to initialize JPA EntityManagerFactory: Property 'com.Comment.ticket' is not a collection and may not be a '@OneToMany', '@ManyToMany', or '@ElementCollection'
ticket_sys  | 2024-12-23T09:54:07.826Z  WARN 1 --- [ticket_sys_backend] [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Property 'com.Comment.ticket' is not a collection and may not be a '@OneToMany', '@ManyToMany', or '@ElementCollection'
ticket_sys  | 2024-12-23T09:54:07.826Z  INFO 1 --- [ticket_sys_backend] [           main] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown initiated...
ticket_sys  | 2024-12-23T09:54:07.862Z  INFO 1 --- [ticket_sys_backend] [           main] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown completed.
ticket_sys  | 2024-12-23T09:54:07.864Z  INFO 1 --- [ticket_sys_backend] [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
ticket_sys  | 2024-12-23T09:54:07.871Z  INFO 1 --- [ticket_sys_backend] [           main] .s.b.a.l.ConditionEvaluationReportLogger :
ticket_sys  |
ticket_sys  | Error starting ApplicationContext. To display the condition evaluation report re-run your application with 'debug' enabled.
ticket_sys  | 2024-12-23T09:54:07.879Z ERROR 1 --- [ticket_sys_backend] [           main] o.s.boot.SpringApplication               : Application run failed
ticket_sys  |
ticket_sys  | org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Property 'com.Comment.ticket' is not a collection and may not be a '@OneToMany', '@ManyToMany', or '@ElementCollection'
ticket_sys  |       at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1802) ~[spring-beans-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:601) ~[spring-beans-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:523) ~[spring-beans-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:336) ~[spring-beans-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:288) ~[spring-beans-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:334) ~[spring-beans-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:204) ~[spring-beans-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:970) ~[spring-context-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:627) ~[spring-context-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[spring-boot-3.4.0.jar!/:3.4.0]
ticket_sys  |       at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:752) ~[spring-boot-3.4.0.jar!/:3.4.0]
ticket_sys  |       at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:439) ~[spring-boot-3.4.0.jar!/:3.4.0]
ticket_sys  |       at org.springframework.boot.SpringApplication.run(SpringApplication.java:318) ~[spring-boot-3.4.0.jar!/:3.4.0]
ticket_sys  |       at org.springframework.boot.SpringApplication.run(SpringApplication.java:1361) ~[spring-boot-3.4.0.jar!/:3.4.0]
ticket_sys  |       at org.springframework.boot.SpringApplication.run(SpringApplication.java:1350) ~[spring-boot-3.4.0.jar!/:3.4.0]
ticket_sys  |       at sz.backend.System_zgloszen_backend.SystemZgloszenBackendApplication.main(SystemZgloszenBackendApplication.java:10) ~[!/:0.0.1-SNAPSHOT]
ticket_sys  |       at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
ticket_sys  |       at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
ticket_sys  |       at org.springframework.boot.loader.launch.Launcher.launch(Launcher.java:102) ~[zgloszenia.jar:0.0.1-SNAPSHOT]
ticket_sys  |       at org.springframework.boot.loader.launch.Launcher.launch(Launcher.java:64) ~[zgloszenia.jar:0.0.1-SNAPSHOT]
ticket_sys  |       at org.springframework.boot.loader.launch.JarLauncher.main(JarLauncher.java:40) ~[zgloszenia.jar:0.0.1-SNAPSHOT]
ticket_sys  | Caused by: org.hibernate.AnnotationException: Property 'com.Comment.ticket' is not a collection and may not be a '@OneToMany', '@ManyToMany', or '@ElementCollection'
ticket_sys  |       at org.hibernate.boot.model.internal.CollectionBinder.determineSemanticJavaType(CollectionBinder.java:1121) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.internal.CollectionBinder.determineCollectionClassification(CollectionBinder.java:1013) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.internal.CollectionBinder.createBinderAutomatically(CollectionBinder.java:855) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.internal.CollectionBinder.getCollectionBinder(CollectionBinder.java:848) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.internal.CollectionBinder.bindCollection(CollectionBinder.java:284) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.internal.PropertyBinder.bindProperty(PropertyBinder.java:897) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.internal.PropertyBinder.buildProperty(PropertyBinder.java:811) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.internal.PropertyBinder.processElementAnnotations(PropertyBinder.java:732) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.internal.EntityBinder.processIdPropertiesIfNotAlready(EntityBinder.java:1086) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.internal.EntityBinder.handleIdentifier(EntityBinder.java:418) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.internal.EntityBinder.bindEntityClass(EntityBinder.java:250) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.internal.AnnotationBinder.bindClass(AnnotationBinder.java:401) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl.processEntityHierarchies(AnnotationMetadataSourceProcessorImpl.java:257) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.process.spi.MetadataBuildingProcess$1.processEntityHierarchies(MetadataBuildingProcess.java:281) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:324) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1431) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1502) ~[hibernate-core-6.6.2.Final.jar!/:6.6.2.Final]
ticket_sys  |       at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:66) ~[spring-orm-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:390) ~[spring-orm-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:419) ~[spring-orm-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:400) ~[spring-orm-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:366) ~[spring-orm-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1849) ~[spring-beans-6.2.0.jar!/:6.2.0]
ticket_sys  |       at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1798) ~[spring-beans-6.2.0.jar!/:6.2.0]
ticket_sys  |       ... 20 common frames omitted

I’ve searched few guides and tutorial but doesn’y seem to work on my porject. Not sure if relationship XML is necessary or nah. I’d appreciate any help.