根据spring jpa中的实体从多个表中获取数据
我有三个实体，如下所示：
注释：
@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; } 话题：
@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 { }
我该如何实现这一目标？ 我已经看过使用@query的示例和使用searchByAnd的一些示例searchByAnd...但是更令人困惑的是要遵循哪种方法。
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 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; }
库：
评论喜欢回购：
@Repository public interface CommentLikeRepository extends JpaRepository{ CommentLikes findByCommentId(long commentId); }
评论回复回购：
@Repository public interface CommentReplyRepository extends JpaRepository { CommentReply findByReplyId(String replyId); @Transactional Long deleteByReplyId(String replyId); }
评论回购：
@Repository public interface CommentRepository extends JpaRepository{ List findByTopicId(String topicId); CommentBean findByCommentId(long commentId); @Transactional Long deleteByCommentId(long deleteId); }
主题回购：
@Repository public interface TopicRepository extends JpaRepository { TopicBean findByTopicId(String topicId); @Transactional Long deleteByTopicId(String topicId); List findByUsername(String username); }
用户信息回购：
@Repository public interface UserInfoRepository extends JpaRepository{ UserInfo findByUsername(String username); UserInfo findRoleByUsername(String username); }
由于您的标签包括spring-boot和spring-jpa 。
我假设你可以使用spring数据库
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 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 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，上面的重写基于我可以根据原始实体做出的最合理的猜测。
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，另外两个也将被检索。
topicBeanRepo.findAll()