Spring引导JPA相关实体说明

Question

我有一个类似Process的实体，它将由创建，并由一个用户更新。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规范来应用动态过滤器时，我得到了的异常

No property CREATED found for type Process!

@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，我得到以下错误。我是JPA和hibernate的新手，关系映射非常混乱，请帮忙。

@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，我得到以下错误Referenced property not a (One|Many)ToOne: com.app.users.details.domain.UserDetails.id in mappedBy of com.app.scenarios.domain.Process.CREATED

请告诉我我做错了什么。我有一个流程，可以由用户创建，也可以由用户更新。在DB中，我有一个进程和userdetails实体的外键关系。

编辑

使用JPA规范从DB获取过滤数据的代码

Page<process> result = this.processDao.findAll(getprocessGridData(processSearchCondition.getprocessName()), pageRequest);

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

Answer 1

我想你真正想要的是：

@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;
}