我有这些表:
我的意图是:用户可以是公司
或个人
,但他们每个人都有一些共同点,例如用户名,即电子邮件
和 password
,因此我使用 JPA 工具从表中生成实体,结果如下:
public class User implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private int id;
private String email;
private String password;
private int reputation;
//bi-directional one-to-one association to Company
@OneToOne(mappedBy="user", cascade={CascadeType.ALL})
private Company company;
//bi-directional many-to-one association to Location
@OneToMany(mappedBy="user")
private List<Location> locations;
//bi-directional one-to-one association to Person
@OneToOne(mappedBy="user")
private Person person;
//bi-directional many-to-one association to Product
@OneToMany(mappedBy="user")
private List<Product> products;
//bi-directional many-to-one association to UserType
@ManyToOne
@JoinColumn(name="type")
private UserType userType;
//bi-directional many-to-one association to UserPhone
@OneToMany(mappedBy="user")
private List<UserPhone> userPhones;
//bi-directional many-to-one association to UserPicture
@OneToMany(mappedBy="user")
private List<UserPicture> userPictures;
//bi-directional many-to-one association to UserSocialNetwork
@OneToMany(mappedBy="user")
private List<UserSocialNetwork> userSocialNetworks;
// getter and setters
}
现在,如果我尝试保留用户对象,则会在 EclipseLink 中启动以下异常:
Exception [EclipseLink-48] (Eclipse Persistence Services - 2.3.0.v20110604-r9504): org.eclipse.persistence.exceptions.DescriptorException
Exception Description: Multiple writable mappings exist for the field [COMPANY.id_user]. Only one may be defined as writable, all others must be specified read-only.
Mapping: org.eclipse.persistence.mappings.OneToOneMapping[user]
Descriptor: RelationalDescriptor(entity.Company --> [DatabaseTable(COMPANY)])
Exception [EclipseLink-48] (Eclipse Persistence Services - 2.3.0.v20110604-r9504): org.eclipse.persistence.exceptions.DescriptorException
Exception Description: Multiple writable mappings exist for the field [PERSON.id_user]. Only one may be defined as writable, all others must be specified read-only.
Mapping: org.eclipse.persistence.mappings.OneToOneMapping[user]
Descriptor: RelationalDescriptor(entity.Person --> [DatabaseTable(PERSON)])
Runtime Exceptions:
生成的映射是否错误? 我该如何解决这个异常?
更新
public class Company implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="id_user")
private int idUser;
private String email;
private String name;
//bi-directional many-to-one association to Area
@ManyToOne
@JoinColumn(name="area")
private Area areaBean;
//bi-directional one-to-one association to User
@OneToOne(cascade={CascadeType.ALL})
@JoinColumn(name="id_user", insertable=false, updatable=false)
private User user;
// getter and setters
}
@Entity
public class Person implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="id_user")
private int idUser;
@Temporal( TemporalType.DATE)
private Date birthdate;
private String gender;
private String name;
private String surname;
//bi-directional one-to-one association to User
@OneToOne
@JoinColumn(name="id_user", insertable=false, updatable=false)
private User user;
// getters and setters
}
最佳答案
我解决了将 insertable=false, updatable=false
放置在两个类 Person 和 的 @JoinColumn
注释中的问题>公司。
关于jpa - EclipseLink 中的多个可写映射异常,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/7952115/