java.sql.SQLIntegrityConstraintViolationException：無法添加或更新子行：外鍵約束失敗

Question

我是Spring MVC的初學者，但遇到錯誤但無法解決。有人可以提供代碼幫助。

JSP頁面，我們在其中輸入存儲在數據庫中的發言人詳細信息的值

   <form class="form-horizontal bucket-form" id="myform" method="post" 
    action="spkr">
       <div class="control-label text-center">
            <p class="required"><em>required fields</em></p></div>
                <div class="form-group">    
                    <label class="col-sm-3 control-label required">First 
                Name</label>
                    <div class="col-sm-6">
                        <input type="text" name="firstname" id="firstname" class="form-control">
                    </div>
                </div>
                <div class="form-group">    
                <label class="col-sm-3 control-label required">Last Name</label>
                    <div class="col-sm-6">
                        <input type="text" name="lastname" id="lastname" class="form-control">
                    </div>
                </div>
                <div class="form-group">
                     <label class="col-sm-3 control-label required">DOB</label>
                    <div class="col-sm-3">
                        <input type="text" class="form-control" id="focusedInput" name="dob" type="text" value="">
                    </div> 
                </div>
                <div class="form-group">
                     <label class="col-sm-3 control-label required">Gender</label>                      
                         <span style="padding-left:15px">
                            <label class="radio-inline">
                                <input type="radio" name="gender" id="gender"   >
                                Male
                            </label>
                            <label class="radio-inline">
                                <input type="radio" name="gender" id="gender" >
                                Female
                            </label>
                        </span>
                </div>
                <div class="form-group">
                    <label class="col-sm-3 control-label required">Email id</label>
                    <div class="col-sm-6">
                        <input type="email" class="form-control" placeholder="" name="mail" id="mail" >
                    </div>
                </div>
                <div class="form-group">
                    <label class="col-sm-3 control-label required">Profession</label>
                    <div class="col-sm-6">
                        <input type="text" class="form-control" placeholder="" name="prof" id="prof" >
                    </div>
                </div>
                <div class="form-group">
                    <label class="col-sm-3 control-label ">Organisation</label>
                    <div class="col-sm-6">
                        <input type="text" name="org" id="org" class="form-control" placeholder="eg:Tech Mahindra">
                    </div>
                </div>
                <div class="form-group">
                    <label class="col-sm-3 control-label ">Experience</label>
                    <div class="col-sm-6">
                        <input type="number" class="form-control" min="0" name="exp" id="exp" placeholder="">
                    </div>
                </div>

                <div class="form-group">
                    <label class="col-sm-3 control-label required">Achievements</label>
                    <div class="col-sm-6">
                        <textarea class="form-control" rows="5" name="ach" id="ach" placeholder=""></textarea>
                    </div>
                </div>
                <div class="form-group">
                     <label class="col-sm-3 control-label required">Event ID</label>
                    <div class="col-sm-3">
                        <input type="number" class="form-control" name="eid" id="eid" >
                    </div> 
                </div>

                <div class="form-group"> 
                    <label class="col-sm-3 control-label">Upload image</label>
                    <div class="col-sm-6">
                        <input type="file" class="form-control" id="forImage" accept="image/*">
                    </div>
                </div>                  
                <div class="form-group">
                    <div class="col-lg-offset-3 col-lg-6">
                        <button class="btn btn-primary" id="speakerSubmit" type="submit">Save</button>
                        <button type="reset" class="btn btn" onClick="myFunction()">Reset</button>
                        <script type="text/javascript">
                            function myFunction() {
                            document.getElementById("myform").reset();
                            }
                        </script>
                    </div>
                </div>

            </form>

POJO課

  package com.ems.DO;
  import javax.persistence.CascadeType;
  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.OneToOne;
  import javax.persistence.Table;
  @Entity
  @Table(name="ems_spkr_tbl")
  public class Speaker {
  @Id
  @GeneratedValue(strategy=GenerationType.IDENTITY)
  @Column(name="SPKR_ID",nullable=false)
  private int speakerId;
  @Column(name="FNAME")
  private String firstname;
  @Column(name="LNAME")
  private String lastname;
  @Column(name="GENDER")
  private String gender;
  /*private String DOB;*/
  @Column(name="SPKR_MAILID")
  private String mail;
  @Column(name="PROFESSION")
  private String prof;
  @Column(name="ORGN")
  private String org;
  @Column(name="EXP")
  private String exp;
  @Column(name="ACHIEVMNTS")
  private String ach;
  @Column(name="SPKR_EVNT_ID")
  private int eid;

    public Speaker(){

    }

    public Speaker(int speakerId, String firstname, String lastname, String 
     gender, String mail, String prof,String org, String exp, String ach, 
     int eid) {
        super();
        this.speakerId = speakerId;
        this.firstname= firstname;
        this.lastname = lastname;
        this.gender = gender;
        this.mail = mail;
        this.prof = prof;
        this.org = org;
        this.exp = exp;
        this.ach = ach;
        this.eid = eid;
    }

    public int getSpeakerId() {
        return speakerId;
    }

    public void setSpeakerId(int speakerId) {
        this.speakerId = speakerId;
    }



    public String getFirstname() {
        return firstname;
    }

    public void setFirstname(String firstname) {
        this.firstname = firstname;
    }



    public String getLastname() {
        return lastname;
    }

    public void setLastname(String lastname) {
        this.lastname = lastname;
    }



    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }



    public String getMail() {
        return mail;
    }

    public void setMail(String mail) {
        this.mail = mail;
    }



    public String getProf() {
        return prof;
    }

    public void setProf(String prof) {
        this.prof = prof;
    }



    public String getOrg() {
        return org;
    }

    public void setOrg(String org) {
        this.org = org;
    }



    public String getExp() {
        return exp;
    }

    public void setExp(String exp) {
        this.exp = exp;
    }



    public String getAch() {
        return ach;
    }

    public void setAch(String ach) {
        this.ach = ach;
    }




    public int getEid() {
        return eid;
    }

    public void setEid(int eid) {
        this.eid = eid;
    }
    }

SpeakerService

 package com.ems.service;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import com.ems.DO.Speaker;
import com.ems.dao.SpeakerDao;
@Repository
public class SpeakerServiceImpl implements SpeakerService{

@Autowired
SpeakerDao speakerDao;

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

public boolean add(Speaker s) {
    boolean status=speakerDao.add(s);
    return status;

}
}

SpeakerDaoClass

  package com.ems.dao;
  import java.util.List;
  import org.hibernate.Query;
  import org.hibernate.Session;
  import org.hibernate.SessionFactory;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.stereotype.Repository;
  import org.hibernate.cfg.Configuration;

  import com.ems.DO.Speaker;

 @Repository
 public class SpeakerDaoImpl implements SpeakerDao{

  @Autowired
  private SessionFactory sessionFactory;


public SpeakerDaoImpl(SessionFactory sessionFactory) {
    this.sessionFactory = sessionFactory;
}


public void setSessionFactory(SessionFactory sessionFactory) {
       this.sessionFactory = sessionFactory;
}

 public boolean add(Speaker s) {

Session session = sessionFactory.getSessionFactory().openSession();
session.save(s);
System.out.println("one record inserted");
return true;
 }
  }

錯誤結果

java.sql.SQLIntegrityConstraintViolationException：不能添加或更新子行，外鍵約束失敗（ emsdataschema 。 ems_spkr_tbl ，約束SPKR_EVNT_ID外鍵（ SPKR_EVNT_ID ）參考ems_evnt_tbl_ai （ EVNT_ID ）ON DELETE CASCADE ON UPDATE CASCADE）

我只輸入了參考值，但它給出了一個例外:-(請檢查代碼並提出可能的解決方案。在此先感謝

Answer 1

好像未指定eid或引用了不存在的ID。 檢查它是否為空，並包含ems_evnt_tbl_ai表中存在的ID。

定義Event實體並設置適當的關系可能會更好。