休眠中的 OnetoOne 和 OneToMany

Question

我有两个实体类用户和钱包数据我想通过注释将一个用户与多个钱包建立关系，但我不知道如何。还有我想通过位于用户实体中的签名字段传递的关系。

@Entity(name = "wallet_data")
public class WalletData implements Serializable
{

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    @Column(name = "amount")
    private Double amount;
    @Column(name = "currency")
    private String currency;
    @JoinColumn(table = "user",referencedColumnName = "signature")
    private User user; //Each wallet know who is his owner user

和

@Entity
@Table(name = "user")
@XmlRootElement
@NamedQueries(
        {
            @NamedQuery(name = "User.findAll", query = "SELECT u FROM User u"),
            @NamedQuery(name = "User.findById", query = "SELECT u FROM User u WHERE u.id = :id"),
            @NamedQuery(name = "User.findByUsername", query = "SELECT u FROM User u WHERE u.username = :username"),
            @NamedQuery(name = "User.findByPassword", query = "SELECT u FROM User u WHERE u.password = :password"),
            @NamedQuery(name = "User.authorize", query = "SELECT u FROM User u WHERE u.password = :password and u.username = :username")
        })
public class User implements Serializable
{

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "id")
    private Integer id;
    @Basic(optional = false)
    @Column(name = "username")
    private String username;
    @Basic(optional = false)
    @Column(name = "password")
    private String password;
    @Column(name = "signature")
    private String signature;
    @JoinColumn(name = "user_id", referencedColumnName = "id")
    @OneToOne(targetEntity = UserData.class)
    private UserData userId;
    @OneToMany(targetEntity = WalletData.class, cascade = CascadeType.ALL,mappedBy = "id")
    private Set<WalletData> wallets; //The set contain all wallets of the current user

Answer 1

您忘记了 WalletData.user 上的 @ManyToOne 注释。

而 mappedBy 属性应该是 user，因为这是构成关联另一方的字段。

文档中描述了双向 OneToMany 关联。阅读：http://docs.jboss.org/hibernate/orm/4.3/manual/en-US/html_single/#d5e5564

休眠中的 OnetoOne 和 OneToMany

OnetoOne and OneToMany in hibernate

hibernate

one-to-one

one-to-many