空外键，在使用 hibernate [4.1.1] 注释的 ManyToOne 关系中

我试图使用坚持一对多和多对一的关系休眠4.1.1但外键始终是NULL.

有两个实体：Account and Client. A Client可以有多个Accounts同时Account恰好有一个Client.

以下是课程（仅重要的）：

账户.java

@Entity
@Table(name = "account")
public class Account implements Serializable {
    private Client client;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    public long getId() {
        return id;
    }

    @ManyToOne
    @JoinColumn(name = "id_client")
    public Client getClient() {
        return client;
    }
}

客户端.java

@Entity
@Table(name = "client")
public class Client implements Serializable {
    private List<Account> accounts;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    public long getId() {
        return id;
    }

    @OneToMany(mappedBy = "client", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    public List<Account> getAccounts() {
        return accounts;
    }
}

测试.java

session.beginTransaction();

Client client = new Client();
Account account1 = new Account();
Account account2 = new Account();

a.addAccount(account1);
a.addAccount(account2);

session.save(client);
session.getTransaction().commit();

运行时，Hibernate 将外键添加到表中：

Hibernate: alter table account add index FKB9D38A2D3B988D48 (id_client), add constraint FKB9D38A2D3B988D48 foreign key (id_client) references client (id)

两个帐户都有 id_client 列NULL.

我尝试把可空 = false@JoinColumn 关系，但这只是调用了一个异常。

Exception in thread "main" org.hibernate.exception.ConstraintViolationException: Column 'id_client' cannot be null

弄清楚了。我忘记将客户添加到帐户中。

account1.setClient(client);
account2.setClient(client);

现在可以了。感谢您的小费。 ;)