所以我有4张桌子
雇主
@Entity
@EqualsAndHashCode(callSuper = false)
@Table(name = "employers")
@NoArgsConstructor
@AllArgsConstructor
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler", "jobPostings"})
@PrimaryKeyJoinColumn(name="employer_id", referencedColumnName = "id")
public class Employer extends User {
@Column(name = "company_name")
private String companyName;
@Column(name = "website")
private String website;
@Column(name = "phone_number")
private String phoneNumber;
@OneToMany(mappedBy="employer")
private List<JobPosting> jobPostings;
}
一座城市
@Data
@Entity
@Table(name="cities")
@AllArgsConstructor
@NoArgsConstructor
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler", "jobPostings"})
public class City {
@Id
@Column(name="id")
private int id;
@Column(name="city_name")
private String cityName;
@OneToMany(mappedBy="city")
private List<JobPosting> jobPostings;
}
工作职位
@AllArgsConstructor
@Data
@Entity
@Table(name="job_positions")
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler", "jobPostings"})
public class JobPosition {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="job_position_id")
private int id;
@Column(name="title")
private String title;
@OneToMany(mappedBy="jobPosition")
private List<JobPosting> jobPostings;
}
还有一个 JobPosting（如招聘广告）
@Entity
@Table(name="job_postings")
@Data
@NoArgsConstructor
@AllArgsConstructor
//@JsonIgnoreProperties({"hibernateLazyInitializer", "handler", "city", "jobPosition","employer"})
public class JobPosting {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name="id")
private int id;
@Column(name="job_requirements")
private String jobRequirements;
@Column(name="salary_min")
private int salaryMin;
@Column(name="salary_max")
private int salaryMax;
@Column(name="application_deadline")
private LocalDate applicationDeadline;
@Column(name="number_of_openings")
private int numberOfOpenings;
@Column(name="stream_date")
private LocalDate streamDate;
@ManyToOne()
@JoinColumn(name="city_id")
private City city;
@ManyToOne()
@JoinColumn(name="job_position_id")
private JobPosition jobPosition;
@ManyToOne()
@JoinColumn(name= "employer_id")
private Employer employer;
}
我已经为所有这些实现了必要的映射，并且工作正常。但是，我想将他们加入 DTO，例如：
@Data
@AllArgsConstructor
@NoArgsConstructor
public class JobPostingWithJobPositionCityEmployerDto {
private int id;
private String jobRequirements;
private int salaryMin;
private int salaryMax;
private LocalDate applicationDeadline;
private int numberOfOpenings;
private LocalDate streamDate;
private String cityName;
private String title;
private String companyName;
}
为了以更干净的方式获取我想要的字段，我正在尝试使用 springframework.jpa 的 @Query 注释，但由于我刚刚了解到这一点，所以我无法完全管理它，我正在使用的查询是：
@Query(value ="Select new kodlamaio.hrms.entities.dtos.JobPostingWithJobPositionCityEmployerDto"
+ "(j.id, j.jobRequirements, j.salaryMin, j.salaryMax, j.numberOfOpenings, j.streamDate, j.applicationDeadline, c.cityName, p.title, e.companyName)"
+ " From Employer e Inner Join e.jobPostings j, "
+ "From City c Inner Join c.jobPostings j, "
+ "From JobPosition p Inner Join p.jobPostings j", nativeQuery = true)
List<JobPostingWithJobPositionCityEmployerDto> getJobPostings();
我什至不知道这是否是正确的方法，我不断收到语法错误，我查找了答案但无法完全理解他们在说什么，有很多不同的场景。因此，如果有人可以帮助我处理这个查询并推荐一些资源来了解不同的命令，我将非常感激，在此先感谢。