與左連接的JPQL查詢

Question

我想創建一個JPQL查詢，將兩個表連接在一起，我可以在其中設置數據。

public void uploadSaveGame(User user, String saveData) 
    { 
     EntityTransaction entr=em.getTransaction(); 
     entr.begin(); 

     try{ 
      Query query = em.createQuery("UPDATE Saves s SET s.save = :saveData" + 
"WHERE s.login = :user in (select sa.saveid,sa.Users.login, sa.savedata from Saves sa " 
       + "LEFT JOIN sa.Users m WHERE sa.saves = m.users.saveid)", Save.class); 
     query.setParameter("login", user); 
     query.setParameter("saveData", saveData); 
     query.executeUpdate(); 
     entr.commit(); 

     }catch(Exception e){ 
      entr.rollback(); 
     } 

    } 

我有這樣的entites：

/* 
* To change this license header, choose License Headers in Project Properties. 
* To change this template file, choose Tools | Templates 
* and open the template in the editor. 
*/ 
package com.dke.ps.Tables; 

import java.io.Serializable; 
import java.util.Collection; 
import javax.persistence.Basic; 
import javax.persistence.Column; 
import javax.persistence.Entity; 
import javax.persistence.GeneratedValue; 
import javax.persistence.GenerationType; 
import javax.persistence.Id; 
import javax.persistence.JoinColumn; 
import javax.persistence.ManyToOne; 
import javax.persistence.NamedQueries; 
import javax.persistence.NamedQuery; 
import javax.persistence.OneToMany; 
import javax.persistence.Table; 
import javax.xml.bind.annotation.XmlRootElement; 
import javax.xml.bind.annotation.XmlTransient; 

/** 
* 
* @author michal 
*/ 
@Entity 
@Table(name = "saves") 
@XmlRootElement 
@NamedQueries({ 
    @NamedQuery(name = "Saves.findAll", query = "SELECT s FROM Saves s") 
    , @NamedQuery(name = "Saves.findBySaveid", query = "SELECT s FROM Saves s WHERE s.saveid = :saveid") 
    , @NamedQuery(name = "Saves.findBySavedata", query = "SELECT s FROM Saves s WHERE s.savedata = :savedata")}) 
public class Saves implements Serializable { 

    private static final long serialVersionUID = 1L; 
    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    @Basic(optional = false) 
    @Column(name = "saveid") 
    private Integer saveid; 
    @Column(name = "savedata") 
    private String savedata; 
    @JoinColumn(name = "userid", referencedColumnName = "userid") 
    @ManyToOne(optional = false) 
    private Users userid; 
    @OneToMany(mappedBy = "saveid") 
    private Collection<Users> usersCollection; 

    public Saves() { 
    } 

    public Saves(Integer saveid) { 
     this.saveid = saveid; 
    } 

    public Integer getSaveid() { 
     return saveid; 
    } 

    public void setSaveid(Integer saveid) { 
     this.saveid = saveid; 
    } 

    public String getSavedata() { 
     return savedata; 
    } 

    public void setSavedata(String savedata) { 
     this.savedata = savedata; 
    } 

    public Users getUserid() { 
     return userid; 
    } 

    public void setUserid(Users userid) { 
     this.userid = userid; 
    } 

    @XmlTransient 
    public Collection<Users> getUsersCollection() { 
     return usersCollection; 
    } 

    public void setUsersCollection(Collection<Users> usersCollection) { 
     this.usersCollection = usersCollection; 
    } 

    @Override 
    public int hashCode() { 
     int hash = 0; 
     hash += (saveid != null ? saveid.hashCode() : 0); 
     return hash; 
    } 

    @Override 
    public boolean equals(Object object) { 
     // TODO: Warning - this method won't work in the case the id fields are not set 
     if (!(object instanceof Saves)) { 
      return false; 
     } 
     Saves other = (Saves) object; 
     if ((this.saveid == null && other.saveid != null) || (this.saveid != null && !this.saveid.equals(other.saveid))) { 
      return false; 
     } 
     return true; 
    } 

    @Override 
    public String toString() { 
     return "com.dke.ps.Tables.Saves[ saveid=" + saveid + " ]"; 
    } 

} 

和用戶等級：

/* 
* To change this license header, choose License Headers in Project Properties. 
* To change this template file, choose Tools | Templates 
* and open the template in the editor. 
*/ 
package com.dke.ps.Tables; 

import java.io.Serializable; 
import java.util.Collection; 
import java.util.Date; 
import javax.persistence.Basic; 
import javax.persistence.CascadeType; 
import javax.persistence.Column; 
import javax.persistence.Entity; 
import javax.persistence.Id; 
import javax.persistence.JoinColumn; 
import javax.persistence.ManyToOne; 
import javax.persistence.NamedQueries; 
import javax.persistence.NamedQuery; 
import javax.persistence.OneToMany; 
import javax.persistence.Table; 
import javax.persistence.Temporal; 
import javax.persistence.TemporalType; 
import javax.xml.bind.annotation.XmlRootElement; 
import javax.xml.bind.annotation.XmlTransient; 

/** 
* 
* @author michal 
*/ 
@Entity 
@Table(name = "users") 
@XmlRootElement 
@NamedQueries({ 
    @NamedQuery(name = "Users.findAll", query = "SELECT u FROM Users u") 
    , @NamedQuery(name = "Users.findByUserid", query = "SELECT u FROM Users u WHERE u.userid = :userid") 
    , @NamedQuery(name = "Users.findByLogin", query = "SELECT u FROM Users u WHERE u.login = :login") 
    , @NamedQuery(name = "Users.findByPassword", query = "SELECT u FROM Users u WHERE u.password = :password") 
    , @NamedQuery(name = "Users.findByEmail", query = "SELECT u FROM Users u WHERE u.email = :email") 
    , @NamedQuery(name = "Users.findByDate", query = "SELECT u FROM Users u WHERE u.date = :date")}) 
public class Users implements Serializable { 

    private static final long serialVersionUID = 1L; 
    @Id 
    @Basic(optional = false) 
    @Column(name = "userid") 
    private Integer userid; 
    @Column(name = "login") 
    private String login; 
    @Column(name = "password") 
    private String password; 
    @Column(name = "email") 
    private String email; 
    @Column(name = "date") 
    @Temporal(TemporalType.DATE) 
    private Date date; 
    @OneToMany(cascade = CascadeType.ALL, mappedBy = "userid") 
    private Collection<Saves> savesCollection; 
    @JoinColumn(name = "saveid", referencedColumnName = "saveid") 
    @ManyToOne 
    private Saves saveid; 

    public Users() { 
    } 

    public Users(Integer userid) { 
     this.userid = userid; 
    } 

    public Integer getUserid() { 
     return userid; 
    } 

    public void setUserid(Integer userid) { 
     this.userid = userid; 
    } 

    public String getLogin() { 
     return login; 
    } 

    public void setLogin(String login) { 
     this.login = login; 
    } 

    public String getPassword() { 
     return password; 
    } 

    public void setPassword(String password) { 
     this.password = password; 
    } 

    public String getEmail() { 
     return email; 
    } 

    public void setEmail(String email) { 
     this.email = email; 
    } 

    public Date getDate() { 
     return date; 
    } 

    public void setDate(Date date) { 
     this.date = date; 
    } 

    @XmlTransient 
    public Collection<Saves> getSavesCollection() { 
     return savesCollection; 
    } 

    public void setSavesCollection(Collection<Saves> savesCollection) { 
     this.savesCollection = savesCollection; 
    } 

    public Saves getSaveid() { 
     return saveid; 
    } 

    public void setSaveid(Saves saveid) { 
     this.saveid = saveid; 
    } 

    @Override 
    public int hashCode() { 
     int hash = 0; 
     hash += (userid != null ? userid.hashCode() : 0); 
     return hash; 
    } 

    @Override 
    public boolean equals(Object object) { 
     // TODO: Warning - this method won't work in the case the id fields are not set 
     if (!(object instanceof Users)) { 
      return false; 
     } 
     Users other = (Users) object; 
     if ((this.userid == null && other.userid != null) || (this.userid != null && !this.userid.equals(other.userid))) { 
      return false; 
     } 
     return true; 
    } 

    @Override 
    public String toString() { 
     return "com.dke.ps.Tables.Users[ userid=" + userid + " ]"; 
    } 

} 

這兩個類是自動的數據庫連接生成。所以，在那個查詢中，我認爲我應該與他們合作，而不是直接與數據庫中的表進行合作。它是如此？

不幸的是，我沒有任何編輯列數據，我不知道問題出在哪裏

我的用戶實體具有多對多的關係與保存實體。

Answer 1

如果您打印您將有例外可能已經注意到，您有:user參數，但你是不是嘗試設置登錄參數

query.setParameter("login", user);