java - JPA， hibernate : OneToOne mapping with foreign key only

Question

环境:

• hibernate 4.1.6.final
• Spring 3.1.2.发布
• Spring JPA 1.1.0.release
• PostgreSQL 9.1-901-1.jdbc4

我决定改写问题。

有2张表:

public company
{
  private Long id;
  private Long name;
  private address table_address;
}
public address
{
  private Long id;
  private String address;
  private Long company_id;
}

注意:两个表id是连续的，没有关联。除了table.address.company_id是公司的外键。

如何做图？我期望的结果是:

"company":{
            "id":4,
            "name":"company name",
            "address":{
                         "id":3,
                         "address":"anywhere",
                         "company_id":4
                      }
          }

那么有人可以教我如何映射这 2 个表吗？

Answer 1

你想要的是 Company 和 Address 之间的一对一映射

只需在 Company 类的 table_address 字段添加 @OneToOne 注解即可:

 public class Address {

        @Id
        @GeneratedValue
        private Long id;
        private String address;
        @OneToOne
        @PrimaryKeyJoinColumn
        private Company company;

        //getters and setters
    }

public class Company {

    @Id
    @GeneratedValue
    private Long id;
    private String name;
    @OneToOne(mappedBy = "company",cascade = CascadeType.ALL)
    private Address companyAddress;

    //getters and setters
}

<子> 除了问题: 尊重 java 命名约定，在您的情况下，类名也应以大写字母开头，变量名中的下一个单词也应如此。即company应该是Company，address应该是Address，private address table_address;更改为 private Address companyAddress;

更新的解决方案

public class Address {

    @Id
    @GeneratedValue
    private Long id;
    private String address;
    @OneToOne
    @JoinColumn(name = "company_id")
    private Company company;

    //getters and setters
}

public class Company {

    @Id
    @GeneratedValue
    private Long id;
    private String name;
    @OneToOne(mappedBy = "company",cascade = CascadeType.ALL)
    private Address companyAddress;

    //getters and setters
}

来自 stupidfrog:如果你使用 @PrimaryKeyJoinColumn，那么 id join 是错误的。 id 与主要但不是地址表 company_id 连接

这里是hibernate的引用 http://docs.jboss.org/hibernate/jpa/2.1/api/javax/persistence/OneToOne.html 示例 1