Question

我有一个用例，两个表有复合主键，一个表与数据库中的另一个表有关系，如何在程序级获得该关系，如何声明bean类

//表Project

的复合主键

    @Embeddable
    @Data
    public class ProjectId implements Serializable {

        private static final long serialVersionUID = 12233365L;

        @Column(name = "PROJECT_CODE")
        private Integer pCode;

        @Column(name = "BOL")
        private String bol;

        @Column(name = "BOLS")
        private String bols;

        @Column(name = "EID")
        private Integer eId;

    }

//项目类

public class Project implements Serializable {

    private static final long serialVersionUID = 748569L;

    @EmbeddedId
    private ProjectId projectId;

    @Column(name = "UPDATED_DATE")
    private Date updatedDate;

    @Column(name = "CREATED_DATE")
    private Date createdDate;

}

// pcode，bol，bols，eId是复合键

//文档表，这里有一些更有趣的项目，文档是＆＃34; pcode，bol，bols，eId +和＃34;

@Embeddable
@Data
public class DocumentId implements Serializable {

    private static final long serialVersionUID = 458933256L;

    @Column(name = "PROJECT_CODE")
    private Integer pCode;

    @Column(name = "BOL")
    private String bol;

    @Column(name = "BOLS")
    private String bols;

    @Column(name = "EID")
    private Integer eId;

    @Column(name = "DID")
    private String dId;
}

//文件表

@Entity
@Table(name = "DOCUMENT")
@Data
public class Documents implements Serializable {

    private static final long serialVersionUID = 14578523695L;

    @EmbeddedId
    private DocumentId documentId;

    @Column(name = "JUR")
    private String jur;

    @Column(name = "DSEQUENCE")
    private Integer dSequence;

    @Column(name = "UPDATED_DATE")
    private Date updatedDate;

    @Column(name = "CREATED_DATE")
    private Date createdDate;

}

两个表之间的关系Document是Project的子表，
我想从项目方面建立一个关系。从文档到项目也很好

我如何映射表之间的一对一关系??

Answer 1

文档表应该包含Project实体的键列（pCode，bol等..）

在Document类上添加此成员：

@OneToOne
@JoinColumns({@JoinColumn(name = "pCode", referencedColumnName = "PROJECT_CODE"),
              @JoinColumn(name = "bol", referencedColumnName = "BOL"),
              @JoinColumn(name = "bols", referencedColumnName = "BOLS"),
              @JoinColumn(name = "eid", referencedColumnName = "EID")})
@MapsId("projectId")
private Project project;

一个映射到复合主键jpa

1 个答案: