JPQL ManyToMany 查询问题（加入 Class）

Question

我在 mysql 上有 table 由 ManyToMany 关联生成。但是当我运行这个查询

select e from Employe e join e.listeRole c inner join c.Role r where r.IdRole = 1

我收到这个错误

13:11:51,959 ERROR [org.jboss.as.ejb3.tx.CMTTxInterceptor] (http-localhost-127.0.0.1-8080-6) javax.ejb.EJBTransactionRolledbackException: org.hibernate.QueryException: could not resolve property: listEmploye of: metier.entities.Employe [select e from metier.entities.Employe e join e.listEmploye c inner join c.Role r where r.IdRole = 1] 13:11:51,960 ERROR [org.jboss.ejb3.invocation] (http-localhost-127.0.0.1-8080-6) JBAS014134: EJB Invocation failed on component Utilisateur for method public abstract java.util.List metier.sess.IUtilisateurLocal.RoleEmploye(): javax.ejb.EJBTransactionRolledbackException: org.hibernate.QueryException: could not resolve property: listEmploye of: metier.entities.Employe [select e from metier.entities.Employe e join e.listEmploye c inner join c.Role r where r.IdRole = 1]

我的类是

 @Entity
 public class Role {

@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Integer IdRole;
private String Intitule;

@ManyToMany(fetch=FetchType.EAGER,mappedBy="listeRole")
private List<Employe> listEmploye=new ArrayList<Employe>();

public Integer getIdRole() {
    return IdRole;
}

public void setIdRole(Integer idRole) {
    IdRole = idRole;
}

public String getIntitule() {
    return Intitule;
}

public void setIntitule(String intitule) {
    Intitule = intitule;
}

public List<Employe> getListEmploye() {
    return listEmploye;
}

public void setListEmploye(List<Employe> listEmploye) {
    this.listEmploye = listEmploye;
}

public Role(String intitule) {
    super();
    Intitule = intitule;
}


public Role() {
    super();
    // TODO Auto-generated constructor stub
}
}

和

@Entity
@DiscriminatorValue(value="employe")
public class Employe extends Utilisateur{
private String TypeEmploye;
private Integer authentification;
private Date logindate;
private Date logoutDate;    
//Employe class
@ManyToMany(fetch=FetchType.EAGER)
private List<Role> listeRole=new ArrayList<Role>();
public String getTypeEmploye() {
    return TypeEmploye;
}
public void setTypeEmploye(String typeEmploye) {
    TypeEmploye = typeEmploye;
}
public Integer getAuthentification() {
    return authentification;
}
public Date getLogindate() {
    return logindate;
}
public void setLogindate(Date logindate) {
    this.logindate = logindate;
}
public Date getLogoutDate() {
    return logoutDate;
}
public void setLogoutDate(Date logoutDate) {
    this.logoutDate = logoutDate;
}
public void setAuthentification(Integer authentification) {
    this.authentification = authentification;
}
public List<Role> getListeRole() {
    return listeRole;
}
public void setListeRole(List<Role> listeRole) {
    this.listeRole = listeRole;
}
public Employe(String username, String password, String email,
        boolean statut, String typeEmploye, Integer authentification,
        List<Role> listeRole) {
    super(username, password, email, statut);
    TypeEmploye = typeEmploye;
    this.authentification = authentification;
    this.listeRole = listeRole;
}
public Employe() {
    super();
    // TODO Auto-generated constructor stub
}}

谢谢你的帮助

Answer 1

对于多对多，您应该按如下方式在拥有方定义可连接对象：

 @ManyToMany
 @JoinTable(name = "emp_roles", joinColumns = {@JoinColumn(name = "emp_id",
               referencedColumnName = "id")}, inverseJoinColumns = {@JoinColumn(name = "role_id",
               referencedColumnName = "id")})
  private List<Role> listeRole;

在您的案例中，这就是该映射应该位于的员工实体。

为什么你有从 Role 到 employee 的引用？我不明白你为什么要使用它，所以我建议你将双向映射更改为单向映射（所以只需将员工列表放在角色实体中）

JPQL ManyToMany 查询问题（加入 Class）

JPQL ManyToMany Query issue (join Class)

java

mysql

jboss

hibernate

jpa