java - JoinColumn Hibernate/API

Question

我遇到以下问题:我想简单地加入表“市场”(主)和“电话”，但在使用注释执行此操作时遇到一些问题。

我只是想使用 Comercio.id 作为 Telefone.fk_id 中相应的外键，但它无法识别它。我还想问是否需要为这两个类创建一个存储库接口(interface)。

编辑。另外，对于这样的示例，POST 请求会是什么样子？

Comercio.java

@Entity
@Table(name = "comercio")
public class Comercio {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String nome;
    private String cnpj;
    private String endereco;

    @OneToMany(targetEntity = Telefone.class , mappedBy = "comercio", fetch = FetchType.LAZY)
    private List<Telefone> telefones;
    private String email;

电话.java

@Entity
@Table(name = "telefone")
public class Telefone {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long telefone_id;

    @ManyToOne
    @JoinColumn(name="fk_id", referencedColumnName = "id")
    private Comercio comercio;
    private String telefone;

我得到的答案:

{
      "nome" : "Americanas",
      "cnpj" : "000",
      "endereco" : "SQN 112",
      "telefones" : [ ],
      "email" : "contato@americanas.com",
      "comercio_id" : 1
}

控制台:

Hibernate: select comercio0_.id as id1_0_, comercio0_.cnpj as cnpj2_0_, comercio0_.email as email3_0_, comercio0_.endereco as endereco4_0_, comercio0_.nome as nome5_0_ from comercio comercio0_
Hibernate: select telefones0_.fk_id as fk_id3_1_0_, telefones0_.telefone_id as telefone1_1_0_, telefones0_.telefone_id as telefone1_1_1_, telefones0_.fk_id as fk_id3_1_1_, telefones0_.telefone as telefone2_1_1_ from telefone telefones0_ where telefones0_.fk_id=**?**

感谢任何帮助。

Answer 1

我建议电话本身并不是一个实体:您永远不会想要查询电话，它仅作为 Comercio 的一部分存在。

它可能是一个Embeddable而不是一个实体，但是因为它只有一个属性 - 数字 - 那么您可以简化为下面的内容并将其映射为字符串集合。这样就不需要 Telefone 类。

@Entity
@Table(name = "comercio")
public class Comercio {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String nome;
    private String cnpj;
    private String endereco;

    @ELementCollection
    @CollectionTable(name = "comercio_telefone", 
                joinColumns=@JoinColumn(name="comercio_id"))
    private List<String> telefones;

    private String email;
}