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我正在尝试使用注释建立多对多关系。 这里有我的实体关于休眠映射的问题
@Entity
public class Publisher{
@Id
public int id;
public String name;
}
@Entity
public class PublisherBook{
@Id
public int id;
@ManyToOne(cascade=CascadeType.ALL)
@JoinColumn(name="bookId",nullable=false)
public Book book;
@ManyToOne(cascade=CascadeType.ALL)
@JoinColumn(name="publisherId",nullable=false)
public Publisher Publisher;
}
@Entity
public class Book{
@Id
public int id;
public String name;
@OneToMany(fetch=FetchType.EAGER, mappedBy="book")
public Set<BookAuthor> authors;
}
@Entity
public class BookAuthor{
@Id
public int id;
@ManyToOne(cascade=CascadeType.ALL)
@JoinColumn(name="bookId",nullable=false)
public Book book;
@ManyToOne(cascade=CascadeType.ALL)
@JoinColumn(name="authorId",nullable=false)
public Author author;
}
@Entity
public class Authors{
@Id
public int id;
public String name;
}
下面是数据的样本集,我有实体
Author:(id,name)
1, Author 1
2, Author 2
3, Author 3
Book: (id, name)
1, Book 1
2, Book 2
3, Book 3
Publisher(id,name)
1, Publisher 1
2, Publisher 2
3, Publisher 3
BookAuthor (id, bookId, authorId)
1, 1, 1
2, 1, 2
3, 1, 3
4, 2, 1
5, 3, 2
PublisherBook(id, publisherId, bookId)
1, 1, 1
2, 1, 2
3, 1, 3
4, 2, 1
5, 3, 2
如果我试图得到出版商1(ID = 1)的所有书籍列表从PublisherBook表中,它应该共返回3本书。 但我总共收到5本书。第1册(ID = 1)被重复3次,不同的作者值(1,2,3) 所以PublisherBook列表返回
1, 1, 1
1, 1, 1
1, 1, 1
2, 1, 2
3, 1, 3
如果我从Book实体删除设置,PublisherBook名单为发布商1返回正确的值
1, 1, 1
2, 1, 2
3, 1, 3
有人可以告诉我我做错了什么吗?对长期职位道歉。