1
Attributes
:电影属性(剧情,惊悚等)(有列:ID,姓名)User
:用户在系统中(有列:ID ,名称)Movie
:有属性相关联(如'矩阵'具有'科幻-60%','惊悚片-40%'等)(具有列:id,attrid,fraction) -attrid
是一个外键到Attributes
Preference
:用户对电影的偏好(具有列:id,uid,movieid,rating) -uid
是外键,User
和movieid
是外键Movie
。
这是模型描述我到目前为止:
User:
@Entity
@Table(name="USER")
public class User extends Model {
@Id
@Column(name = "uid")
public Long uid;
@Column(name = "name")
public String name;
}
Movie Attribute:
@Entity
@Table(name = "MOVIEATTRIBUTE")
public class Attribute extends Model {
@Id
@Column(name = "attrid")
public Long attrid;
@Column(name = "name")
public String name;
@ManyToMany
@JoinColumn(name = "movieid")
public Movie movie;
}
Movie:
@Entity
public class Movie extends Model {
@Id
@Column(name = "movieid")
public Long movieid;
@ManyToMany
@JoinColumn(name = "attrid")
public Attribute attribute;
@Column(name = "rating")
public Integer rating;
}
Preference:
@Entity
public class Preference extends Model {
@Id
@Column(name = "prefid")
public Long prefid;
@ManyToMany
@JoinColumn(name="uid")
public User user;
@ManyToMany
@JoinColumn(name="movieid")
private Movie movie;
@Column(name = "rating")
public Integer rating;
}
我得到以下运行时异常:无法读取偏好注解。
我错过了什么?
谢谢!