Spring boot JPA相关实体说明

Question

我有一个类似实体的流程，由一个用户创建、更新。当我尝试应用过滤器时。我已经在数据库中创建了外键关系。现在，当我使用JPA规范应用动态过滤器时，我得到了一个异常

找不到为类型进程创建的属性

@Table(name = "process")
@Entity
public class Process {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "PROCESS_ID")
    @JsonProperty("id")
    private Long id = null;
    
    @NotNull
    @Column(name = "NAME")
    @JsonProperty("name")
    private String name = null;

    @Column(name = "CREATED_BY", updatable = false)
    @JsonProperty("createdBy")
    private Long createdBy = null;

    @Column(name = "updatedBy", nullable = true)
    @JsonProperty("updatedBy")
    private Long updatedBy = null;
}

因此，我在流程实体中添加了实体关系映射，如下所示，

现在，我发现了错误。我是JPA和hibernate新手，关系映射非常混乱，请帮助。

@Table(name = "process")
@Entity
public class Process {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "PROCESS_ID")
    @JsonProperty("id")
    private Long id = null;
    
    @NotNull
    @Column(name = "NAME")
    @JsonProperty("name")
    private String name = null;

    @Column(name = "CREATED_BY", updatable = false)
    @JsonProperty("createdBy")
    private Long createdBy = null;

    @Column(name = "updatedBy", nullable = true)
    @JsonProperty("updatedBy")
    private Long updatedBy = null;
    
    //newly added below properties so that there will be no error when fetching data
     @OneToOne(targetEntity = UserDetails.class, fetch = FetchType.LAZY, mappedBy = "id")
    private UserDetails CREATED;

    @OneToOne(targetEntity = UserDetails.class, fetch = FetchType.LAZY, mappedBy = "id")
    private UserDetails UPDATED;

}

现在，我得到了以下错误引用的属性，而不是（一个|多个）ToOne:com。应用程序。用户。细节。领域用户详细信息。com的mappedBy中的id。应用程序。情节。领域过程已创建

请让我知道我做错了什么。我有一个流程，可以由用户创建，也可以由用户更新。在DB中，我对process和userdetails实体有一个外键关系。

编辑

使用JPA规范从数据库中获取过滤数据的代码

Page

  private static Specification<process> getprocessGridData(String processName) {
        return (Specification<process>) (root, query, criteriaBuilder) -> (
                criteriaBuilder.like(root.get("name"), processName)
        );
    }




Answer 1

我猜你真正想要的是：

@Table(name = "process")
@Entity
public class Process {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "PROCESS_ID")
    @JsonProperty("id")
    private Long id;
    
    @NotNull
    @Column(name = "NAME")
    @JsonProperty("name")
    private String name;
    
    @OneToOne(fetch = FetchType.LAZY)
    @jOINColumn(name = "CREATED_BY", updatable = false)
    private UserDetails createdBy;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "UPDATED_BY", nullable = true)
    private UserDetails updatedBy;

}