嵌套异常是org.hibernate.AnnotationException: mapappedby引用一个未知的目标实

Question

基于本教程，我尝试使用复合键创建多对多关系最后我得到以下错误

组合键本身具有以下结构:

@Embeddable
@Data
public class MovieRatingsKey implements Serializable {
@Column(name = "movieid")
private Movies movieid;
@Column(name = "userid")
private Usrs userid;
}

类电影:

@Entity
@Data
public class Movies {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer movieid;
/*not related to the question*/
@OneToMany(mappedBy = "movieid", fetch = FetchType.LAZY)
private Set<Ratings> rates = new HashSet<>();
}

用户:

@Entity
@Data
public class Usrs {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer userid;
@OneToMany(mappedBy = "userid", fetch = FetchType.LAZY)
private Set<Ratings> rates = new HashSet<>();
}

关联表:

@Entity
@Data
public class Ratings {
@EmbeddedId
private MovieRatingsKey id;

/*not related to the question*/
@ManyToOne
@MapsId("movieid")
@JoinColumn(name = "movieid")
Movies movie;
@ManyToOne
@MapsId("userid")
@JoinColumn(name = "userid")
Usrs user;
}

Answer 1

在您的Usrs中，您使用的userid在mappedBy中应该是user，如下所示。

@Entity
@Data
public class Usrs {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer userid;
@OneToMany(mappedBy = "user", fetch = FetchType.LAZY)
private Set<Ratings> rates = new HashSet<>();
}