为什么我要将此 "Repeated column in mapping for entity" 获取到 Hibernate 实体中？处理这种情况的最佳方法是什么？
Why am I obtaining this "Repeated column in mapping for entity" into an Hibernate entity? What is the best way to handle this situation?
我不太喜欢 Hibernate，我有以下 problem\doubt。
我有这种情况：
1) 我有这个 Room 实体 class 代表住宿的房间：
@Entity
@Table(name = "room")
public class Room implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Long id;
@ManyToOne
@JoinColumn(name = "id_accomodation_fk", nullable = false)
private Accomodation accomodation;
@ManyToOne
@JoinColumn(name = "id_room_tipology_fk", nullable = false)
private RoomTipology roomTipology;
@OneToMany(mappedBy = "room")
private List<RoomMedia> roomMediaList;
@Column(name = "room_number")
private String number;
@Column(name = "room_name")
private String name;
@Column(name = "room_description")
private String description;
@Column(name = "is_enabled")
private Boolean isEnabled;
........................................................................
........................................................................
GETTER AND SETTER METHODS
........................................................................
........................................................................
}
2) 然后我有这个 RoomMedia 实体 class 表示与特定 Room 实体相关的照片：
@Entity
@Table(name = "room_media")
public class RoomMedia {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Long id;
@Column(name = "id_room")
private Long idRoom;
@ManyToOne
@JoinColumn(name = "id_room", nullable = false) // da rinominare anche sul DB in room_fk
private Room room;
@Lob
@Column(name = "media")
private byte[] media;
private String description;
........................................................................
........................................................................
GETTER AND SETTER METHODS
........................................................................
........................................................................
}
如您在前面的代码中所见，这 2 个实体 class 以这种方式 link 组合在一起：
一个Room实例表示一个特定的房间并包含其照片列表，这样：
@OneToMany(mappedBy = "room")
private List<RoomMedia> roomMediaList;
这意味着一个房间被 link 编辑到许多 RoomMedia 实例。 mappedBy = "room" 表示要在 Room 和 RoomMedia 之间执行 link 使用 room RoomMedia 实体的 字段（表示 RoomMedia 实例的特定房间）。
然后在 RoomMedia 实体 class 我有这个 link:
@ManyToOne
@JoinColumn(name = "id_room", nullable = false)
private Room room;
Where 表示许多 RoomMedia 实例与单个 Room 实例相关。 Join 操作是使用 room_media table 上的 id_room 字段完成的（它在table 级别而不是实体级别）。
如果所有这些推理有问题，请更正。
我的问题是在应用程序启动时我收到了这条错误消息：
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.persistenceException(EntityManagerFactoryBuilderImpl.java:1249)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.access0(EntityManagerFactoryBuilderImpl.java:120)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.perform(EntityManagerFactoryBuilderImpl.java:860)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.perform(EntityManagerFactoryBuilderImpl.java:850)
at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:425)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:849)
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60)
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:353)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:373)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:362)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1642)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1579)
... 39 more
Caused by: org.hibernate.MappingException: Repeated column in mapping for entity: com.betrivius.domain.RoomMedia column: id_room (should be mapped with insert="false" update="false")
at org.hibernate.mapping.PersistentClass.checkColumnDuplication(PersistentClass.java:709)
at org.hibernate.mapping.PersistentClass.checkPropertyColumnDuplication(PersistentClass.java:731)
at org.hibernate.mapping.PersistentClass.checkColumnDuplication(PersistentClass.java:753)
at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:506)
at org.hibernate.mapping.RootClass.validate(RootClass.java:270)
at org.hibernate.cfg.Configuration.validate(Configuration.java:1360)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1851)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.perform(EntityManagerFactoryBuilderImpl.java:857)
... 48 more
为什么 Hibernate 不能处理两者？问题是什么？我该如何解决？
我认为这可能取决于在 RoomMedia 实例中我仍然有 id_room 字段的事实不再需要了，因为在这个实体中我也放了：
@ManyToOne
@JoinColumn(name = "id_room", nullable = false)
private Room room;
它本身包含这个 id。
所以我认为删除这个字段：
@Column(name = "id_room")
private Long idRoom;
我会解决我的问题，是吗？
但现在我可能会遇到另一个问题：在我的 DAO 中，我可能会有一些涉及 idRoom 的复杂查询。因此，为了方便起见，我会将 private Room room; 和 private Long idRoom; 字段都放入我的 RoomMedia实体class.
我怎样才能同时避免这个问题？
您绝对应该从映射中删除此列
@Column(name = "id_room")
private Long idRoom;
Hibernate 告诉你同样的事情。
But now I could will have another problem: into my DAO I could have some complex query that involves the idRoom. So, for convenience, I wold have both these private Room room; and private Long idRoom; field into my RoomMedia entity class.
正确的映射是
@ManyToOne
@JoinColumn(name = "id_room", nullable = false)
private Room room;
和它为您提供所需的一切
查询示例
Query query1 = em.createQuery("select rm from RoomMedia rm where rm.room.id = :id");
Query query2 = em.createQuery("select rm from RoomMedia rm join rm.room r where r.id = :id");
我不太喜欢 Hibernate，我有以下 problem\doubt。
我有这种情况：
1) 我有这个 Room 实体 class 代表住宿的房间：
@Entity
@Table(name = "room")
public class Room implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Long id;
@ManyToOne
@JoinColumn(name = "id_accomodation_fk", nullable = false)
private Accomodation accomodation;
@ManyToOne
@JoinColumn(name = "id_room_tipology_fk", nullable = false)
private RoomTipology roomTipology;
@OneToMany(mappedBy = "room")
private List<RoomMedia> roomMediaList;
@Column(name = "room_number")
private String number;
@Column(name = "room_name")
private String name;
@Column(name = "room_description")
private String description;
@Column(name = "is_enabled")
private Boolean isEnabled;
........................................................................
........................................................................
GETTER AND SETTER METHODS
........................................................................
........................................................................
}
2) 然后我有这个 RoomMedia 实体 class 表示与特定 Room 实体相关的照片：
@Entity
@Table(name = "room_media")
public class RoomMedia {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Long id;
@Column(name = "id_room")
private Long idRoom;
@ManyToOne
@JoinColumn(name = "id_room", nullable = false) // da rinominare anche sul DB in room_fk
private Room room;
@Lob
@Column(name = "media")
private byte[] media;
private String description;
........................................................................
........................................................................
GETTER AND SETTER METHODS
........................................................................
........................................................................
}
如您在前面的代码中所见，这 2 个实体 class 以这种方式 link 组合在一起：
一个Room实例表示一个特定的房间并包含其照片列表，这样：
@OneToMany(mappedBy = "room")
private List<RoomMedia> roomMediaList;
这意味着一个房间被 link 编辑到许多 RoomMedia 实例。 mappedBy = "room" 表示要在 Room 和 RoomMedia 之间执行 link 使用 room RoomMedia 实体的 字段（表示 RoomMedia 实例的特定房间）。
然后在 RoomMedia 实体 class 我有这个 link:
@ManyToOne
@JoinColumn(name = "id_room", nullable = false)
private Room room;
Where 表示许多 RoomMedia 实例与单个 Room 实例相关。 Join 操作是使用 room_media table 上的 id_room 字段完成的（它在table 级别而不是实体级别）。
如果所有这些推理有问题，请更正。
我的问题是在应用程序启动时我收到了这条错误消息：
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.persistenceException(EntityManagerFactoryBuilderImpl.java:1249)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.access0(EntityManagerFactoryBuilderImpl.java:120)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.perform(EntityManagerFactoryBuilderImpl.java:860)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.perform(EntityManagerFactoryBuilderImpl.java:850)
at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:425)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:849)
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60)
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:353)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:373)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:362)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1642)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1579)
... 39 more
Caused by: org.hibernate.MappingException: Repeated column in mapping for entity: com.betrivius.domain.RoomMedia column: id_room (should be mapped with insert="false" update="false")
at org.hibernate.mapping.PersistentClass.checkColumnDuplication(PersistentClass.java:709)
at org.hibernate.mapping.PersistentClass.checkPropertyColumnDuplication(PersistentClass.java:731)
at org.hibernate.mapping.PersistentClass.checkColumnDuplication(PersistentClass.java:753)
at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:506)
at org.hibernate.mapping.RootClass.validate(RootClass.java:270)
at org.hibernate.cfg.Configuration.validate(Configuration.java:1360)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1851)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.perform(EntityManagerFactoryBuilderImpl.java:857)
... 48 more
为什么 Hibernate 不能处理两者？问题是什么？我该如何解决？
我认为这可能取决于在 RoomMedia 实例中我仍然有 id_room 字段的事实不再需要了，因为在这个实体中我也放了：
@ManyToOne
@JoinColumn(name = "id_room", nullable = false)
private Room room;
它本身包含这个 id。
所以我认为删除这个字段：
@Column(name = "id_room")
private Long idRoom;
我会解决我的问题，是吗？
但现在我可能会遇到另一个问题：在我的 DAO 中，我可能会有一些涉及 idRoom 的复杂查询。因此，为了方便起见，我会将 private Room room; 和 private Long idRoom; 字段都放入我的 RoomMedia实体class.
我怎样才能同时避免这个问题？
您绝对应该从映射中删除此列
@Column(name = "id_room")
private Long idRoom;
Hibernate 告诉你同样的事情。
But now I could will have another problem: into my DAO I could have some complex query that involves the idRoom. So, for convenience, I wold have both these private Room room; and private Long idRoom; field into my RoomMedia entity class.
正确的映射是
@ManyToOne
@JoinColumn(name = "id_room", nullable = false)
private Room room;
和它为您提供所需的一切
查询示例
Query query1 = em.createQuery("select rm from RoomMedia rm where rm.room.id = :id");
Query query2 = em.createQuery("select rm from RoomMedia rm join rm.room r where r.id = :id");