Spring Boot JPA ManyToMany MappingException

Question

我想通过ManyToMany关联两个实体。我找到了很多例子（比如这个https://en.wikibooks.org/wiki/Java_Persistence/ManyToMany#Example_of_a_ManyToMany_relationship_annotation或https://vladmihalcea.com/the-best-way-to-use-the-manytomany-annotation-with-jpa-and-hibernate/），甚至在我的代码中有一个其他地方，其中ManyToMany关系似乎有效，但到目前为止我仍然无法想到这一点

我遇到以下异常：

  

引起：org.hibernate.MappingException：外键（FKru66hm0369ayn8dvjj2rgxr9v：user_role [role_id]））必须与引用的主键具有相同的列数（user_role [user_id，role_id]）

班级用户

@Entity
@Table(name = "user")
public class User {

    @Id
    @GeneratedValue
    @Column(name = "user_id")
    private long id;

    @ManyToMany
    @JoinTable(
        name = "user_role",
        joinColumns = @JoinColumn(name = "user_id"),
        inverseJoinColumns = @JoinColumn(name = "role_id"))
    private Set<Role> roles;

    // getters and setters
}

班级角色

@Entity
@Table(name = "user_role")
public class Role {

    @Id
    @GeneratedValue
    @Column(name = "role_id")
    private long id;

    @ManyToMany(mappedBy = "roles")
    private Set<User> users;

    // getters and setters

}

Answer 1

检查this link！

无论如何，问题是你有类角色

@Entity
@Table(name = "user_role")
public class Role {

以及类用户

 @JoinTable(
        name = "user_role",
        joinColumns = @JoinColumn(name = "user_id"),
        inverseJoinColumns = @JoinColumn(name = "role_id"))

两个地方，表名都相同......
那一定是错误的原因......