Question

我有三个实体，如下所示：

评论：

@Entity
@Table(name = "comments")
public class CommentBean implements Serializable {

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @Column(name = "commentId")
    private long commentId;

    @Column(name = "topicId")
    private String topicId;
}

主题：

@Entity
@Table(name = "topics")
public class TopicBean implements Serializable {

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @Column(name = "topicId")
    private String topicId;
    @Column(name = "title")
    private String title;
    @Column(name = "details")
    private String details;
    @Column(name = "username")
    private String username;
    @Column(name = "userImage")
    private String userImage;
    @Column(name = "dayPosted")
    private String dayPosted;
}

喜欢：

@Entity
@Table(name = "comment_likes")
public class CommentLikes implements Serializable {

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

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

    @Column(name = "commentId")
    private long commentId;
}

我希望根据请求从三个表/实体获取所有数据：

@RequestMapping(path = "/get_data_on_login", method = RequestMethod.GET)
public ResponseEntity get_data_on_login()) throws Exception {

}

我如何实现这一目标？我已经看过使用@query的示例和使用searchByAnd...的一些示例，但更令人困惑的是要采用哪种方法。

更新

尝试使用@JoinColumn映射表以使用bean.findAll()获取数据但是，我收到此错误：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1589) ~[spring-beans-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:554) ~[spring-beans-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1081) ~[spring-context-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:856) ~[spring-context-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542) ~[spring-context-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE]
    at seconds47.Application.main(Application.java:24) [classes/:?]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.persistenceException(EntityManagerFactoryBuilderImpl.java:954) ~[hibernate-entitymanager-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:882) ~[hibernate-entitymanager-5.0.11.Final.jar:5.0.11.Final]
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60) ~[spring-orm-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:353) ~[spring-orm-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:373) ~[spring-orm-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:362) ~[spring-orm-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1648) ~[spring-beans-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1585) ~[spring-beans-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    ... 16 more
Caused by: org.hibernate.MappingException: Repeated column in mapping for entity: seconds47.beans.CommentBean column: topicId (should be mapped with insert="false" update="false")
    at org.hibernate.mapping.PersistentClass.checkColumnDuplication(PersistentClass.java:830) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.mapping.PersistentClass.checkPropertyColumnDuplication(PersistentClass.java:848) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.mapping.PersistentClass.checkColumnDuplication(PersistentClass.java:870) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:605) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.mapping.RootClass.validate(RootClass.java:265) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.boot.internal.MetadataImpl.validate(MetadataImpl.java:329) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:443) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:879) ~[hibernate-entitymanager-5.0.11.Final.jar:5.0.11.Final]
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60) ~[spring-orm-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:353) ~[spring-orm-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:373) ~[spring-orm-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:362) ~[spring-orm-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1648) ~[spring-beans-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1585) ~[spring-beans-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    ... 16 more

更新代码：

主题豆：

@Entity
@Table(name = "topics")
public class TopicBean implements Serializable {

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(name = "topicId")
    private String topicId;
    @Column(name = "title")
    private String title;
    @Column(name = "details")
    private String details;
    @Column(name = "username")
    private String username;
    @Column(name = "userImage")
    private String userImage;
    @Column(name = "dayPosted")
    private String dayPosted;

    @OneToMany(mappedBy="topicBean")
    private List<CommentBean> commentBeans;
}

commentBean：

@Entity
@Table(name = "comments")
public class CommentBean implements Serializable {

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(name = "commentId")
    private long commentId;

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

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

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

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

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

    @ManyToOne
    @JoinColumn(name="topicId")
    private TopicBean topicBean;
}

存储库：

评论喜欢回购：

@Repository
public interface CommentLikeRepository extends JpaRepository<CommentLikes, Long>{

    CommentLikes findByCommentId(long commentId);
}

评论回复回购：

@Repository
public interface CommentReplyRepository extends JpaRepository<CommentReply, Long> {

    CommentReply findByReplyId(String replyId);

    @Transactional
    Long deleteByReplyId(String replyId);

}

评论回购：

@Repository
public interface CommentRepository extends JpaRepository<CommentBean, Long>{
    List<CommentBean> findByTopicId(String topicId);
    CommentBean findByCommentId(long commentId);

    @Transactional
    Long deleteByCommentId(long deleteId);
}

主题回购：

@Repository
public interface TopicRepository extends JpaRepository<TopicBean, Long> {
    TopicBean findByTopicId(String topicId);

    @Transactional
    Long deleteByTopicId(String topicId);

    List<TopicBean> findByUsername(String username);
}

用户信息回购：

@Repository
public interface UserInfoRepository extends JpaRepository<UserInfo, Long>{

    UserInfo findByUsername(String username);

    UserInfo findRoleByUsername(String username);
}

Answer 1

由于您的代码包含 spring-boot 和 spring-jpa 。我假设您可以使用 spring数据存储库

发布的实体不以任何方式关联。因此，必须关联实体才能使用一个存储库检索所有数据实体的修改版本如下所示：

评论表

@Entity
@Table(name = "comments")
public class CommentBean implements Serializable {

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @Column(name = "commentId")
    private long commentId;

    @ManyToOne
    @JoinColumn(name="topicId")
    private TopicBean topicBean;

    @OneToMany(mappedBy="commentBean")
    private List<CommentLikes> commentLikesList;
}

主题表

@Entity
@Table(name = "topics")
public class TopicBean implements Serializable {

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @Column(name = "topicId")
    private String topicId;
    @Column(name = "title")
    private String title;
    @Column(name = "details")
    private String details;
    @Column(name = "username")
    private String username;
    @Column(name = "userImage")
    private String userImage;
    @Column(name = "dayPosted")
    private String dayPosted;

    @OneToMany(mappedBy="topicBean")
    private List<CommentBean> commentBeans;
}

comment_likes表

@Entity
@Table(name = "comment_likes")
public class CommentLikes implements Serializable {

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

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

    @ManyToOne
    @JoinColumn(name="commentId")
    private CommentBean commentBean;
}

请注意，上述重写基于我可以根据原始实体做出的最明智的猜测。

现在三个实体正确关联。您可以使用TopicBean存储库来检索所有TopicBeans，也可以检索其他两个 topicBeanRepo.findAll()

根据spring jpa中的实体从多个表中获取数据

1 个答案: