spring - 在具有相似 ID 的 Spring Boot 中加入没有外键的两个表

Question

这里我有两个表；两者都有 ID 作为主键。我想知道如何根据它们的 ID 在没有外键的情况下连接这些表。服务实现应该是什么，存储库中应该有什么？如何使用JOINS 编写@Query？

@Entity
@Table(name = "procedures")
@JsonIgnoreProperties({ "hibernateLazyInitializer", "handler" })
public class Procedure implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "ProcedureId")
    private int id;

    @Column(name = "ProcedureName")
    private String name;
    @Column(name = "ProcedureCode")
    private String code;

    @Column(name = "ProcedureDesc")
    private String desc;
//  getters and setters
}

@Entity
@Table(name = "cliniciandescriptor")
public class CPTClinicianDescriptor {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "Id")
    private int id;

    @Column(name = "ConceptId")
    private int conceptId;

    @Column(name = "CPTCode")
    private String cptCode;

    @Column(name = "ClinicianDescriptorId")
    private int clinicianDescriptorId;


    @Column(name = "ClinicianDescriptor")
    private String clinicianDescriptor;
//  getters and setters
}

Answer 1

您可以像在 SQL 中一样使用 JOIN on 语法

例如

select p from Procedure p join CPTClinicianDescriptor c on c.id = p.id;

在此处阅读有关该主题的更多信息: https://72.services/how-to-join-two-entities-without-mapped-relationship/