Jpa 你有什么问题吗

我和jpa hibernate一起工作 我尝试开发三个类：

但我有一个错误，它与获取类型有关

@Entity
public class Request implements Serializable{


    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer requestId;
    private String detailRequest;

    private String place;



        @ManyToMany(mappedBy="requests",fetch=FetchType.EAGER)
    private List<Expertise> expertises;


...
//getter , setter and constructor
}

---

这是因为实体急于获取专业知识

  @ManyToMany(mappedBy="expertises",fetch=FetchType.EAGER)
    private List<TechnicalSkill> technicalSkills=new ArrayList<TechnicalSkill>();

@ManyToMany（mappedBy=“experties”，fetch=FetchType.EAGER）
private List technicalSkills=new ArrayList（）；

删除“急取”，它将工作

看看这个

@Entity
public class TechnicalSkill implements Serializable{

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

     @Id
     @GeneratedValue(strategy = GenerationType.AUTO)
    private int idTechnicalSkill;
    private String description;
    @ManyToMany
    private List<Expertise> expertises=new ArrayList<Expertise>();

...
//getter , setter and constructor
}

Caused by: org.hibernate.HibernateException: cannot simultaneously fetch multiple bags

  @ManyToMany(mappedBy="expertises",fetch=FetchType.EAGER)
    private List<TechnicalSkill> technicalSkills=new ArrayList<TechnicalSkill>();