Java与Hibernate的外键使用

Question

我正试图开发一个web应用程序，我想知道是否有一种方法可以在不编写大量代码的情况下利用外键。

我的培训。java

@Entity
public class Trainees {

    @Id
    @GeneratedValue
    private int traineesID;
    private int groupsID;
    @ManyToOne
    @JoinColumn(name = "status_trainee")
    private String status_TraineeID;
    private int customersID;
    private String name;
    private String surname;
    private String phoneDetails;
    private String email;

    public Trainees(){

    }

    public Trainees(String name, String surname, String phoneDetails, String email, int id, int groupsID, String status_TraineeID, int customersID) {
        super();
        this.name = name;
        this.surname = surname;
        this.email = email;
        this.phoneDetails = phoneDetails;
        this.groupsID = groupsID;
        this.status_TraineeID = status_TraineeID;
        this.customersID = customersID;
    }

    //getters and setters

    @Override
    public boolean equals(Object object) {
        if (object instanceof Trainees){
            Trainees contact = (Trainees) object;
            return contact.traineesID == traineesID;
        }

        return false;
    }

    @Override
    public int hashCode() {
        return traineesID;
    }
}

status_trainee.java

@Entity
public class Status_Trainee {

    @Id
    @GeneratedValue
    private int status_traineeID;
    private String value;

    public Status_Trainee(){

    }

    public Status_Trainee(String value, int id) {
        super();
        this.value = value;
    }

    //getters and setters

    @Override
    public boolean equals(Object object) {
        if (object instanceof Status_Trainee){
            Status_Trainee value = (Status_Trainee) object;
            return value.status_traineeID == status_traineeID;
        }

        return false;
    }

    @Override
    public int hashCode() {
        return status_traineeID;
    }
}

错误：由：org.hibernate.annotationexception:uaicontacts.model.trainees.status_traineeid上的@onetoone或@manytoone引用了未知实体：String引起

谢谢所有的帮助！

Answer 1

您应该在Strainee中添加对StatusTrainee的引用，并用OneToMany、ManyToOne或OneToone对其进行注释。根据哪种关系，你需要一个statestrainee的列表，或者只是一个statestrainee。

提示：不要在类名中使用下划线。