java - JoinColumn Hibernate/API

我遇到以下问题：我想简单地将表Markets（主）和Telephones联接在一起，但是在使用批注进行操作时却遇到了一些问题。

我只是想将Comercio.id用作Telefone.fk_id的相应外键，但无法识别。我还想问一下是否需要为两个类创建一个存储库接口。

编辑。另外，对于这样的示例，POST请求看起来如何？

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;

Telefone.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" : "[email protected]",
      "comercio_id" : 1
}

安慰：

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。

最佳答案

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

然后，它可能是Embeddable而不是实体，因为它只有一个属性-数字-然后您可以简化为以下内容并将其映射为字符串的集合。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;
}

关于java - JoinColumn Hibernate/API，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/60217911/