简体   繁体   中英

Hibernate joining two tables

I am trying to learn Spring and Hibernate . I have the following form

在此处输入图片说明

After inserting the form values in my database tables, I want them to look like following:

Table Name : student

student_id    studentName
  1.           Jason Stathum

Table Name : studentdetails

studentDetailsid   FatherName   MotherName    student_id
   1                 Mr.X          Mrs. Y        1

But when I actually insert values in my database, the studentdetails table looks like following

Table Name : studentdetails

studentDetailsid   FatherName   MotherName    student_id
   1                 Mr.X          Mrs. Y        NULL

As you can see everything works perfectly but only the student_id column doesn't get filled up. Could you please tell me what I am doing wrong?

Here's are my codes:

Model Class : Student

package com.spring.org.model

@Entity
@Table(name = "student")
public class Student {

@Id 
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name="student_id", nullable= false)
private Integer studentId;
private String studentName;

@OneToMany(cascade = CascadeType.ALL, mappedBy = "student")
private List<StudentDetails> studentDetails = new ArrayList<StudentDetails>();

// Getters and Setters

Model Class : StudentDetails

@Entity
@Table(name = "studentDetails")
public class StudentDetails {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer studentDetailsId;
private String FatherName;
private String MotherName;

@ManyToOne
@JoinColumn(name="student_id")
private Student student;

// Getters and Setters

Controller

 @RequestMapping(value="addstudent", method = RequestMethod.GET)
public String addStudent(@ModelAttribute("secret") Student student, BindingResult result, Model map)
{
    map.addAttribute("student", new Student());     
    return "addStudent";
}

@RequestMapping(value="addstudent", method = RequestMethod.POST)
public String saveStudent(@ModelAttribute("secret") Student student, BindingResult result, Model map)
{
    studentService.addStudent(student);
    map.addAttribute("success", "Submitted");
    return "msg";

}

JSP Page : Form

<c:url var="saveUrl" value="/addstudent" />
 <form:form modelAttribute="secret" method="POST" action="${saveUrl}">
  <table>
  <tr>
     <td><form:label path="studentName">Student Name:</form:label></td>
     <td><form:input path="studentName"/></td>
 </tr> 

 <tr>
    <td><form:label path="studentDetails[0].FatherName">Father Name:</form:label></td>
    <td><form:input path="studentDetails[0].FatherName"/></td>
 </tr>

 <tr>
   <td><form:label path="studentDetails[0].MotherName">Mother Name:</form:label></td>
   <td><form:input path="studentDetails[0].MotherName"/></td>
 </tr>
</table>

 <input type="submit" value="Save" />
</form:form>

StudentDaoImpl

@Override
public void addStudent(Student student) {

    Session session = getSessionFactory().openSession();
    Transaction tx;
    tx = session.beginTransaction();
    session.save(student);  

    tx.commit();
}

Removing the @JoinColumn annotation from the student attribute in StudentDetails should fix the issue:

@ManyToOne
//@JoinColumn(name="student_id")
private Student student;

Change this fragment:

@ManyToOne
@JoinColumn(name="student_id")
private Student student;

to:

@ManyToOne
private Student student;

and this should work.

I have managed to solve the problem, I hope this will help others someday. I made some changes in my

Model Class: Student

@Entity
@Table(name = "student")
public class Student {

@Id 
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name="student_id", nullable= false)
private Integer studentId;
private String studentName;

@OneToMany(cascade = CascadeType.ALL)
@JoinColumn(name="student_id", referencedColumnName="student_id")
private List<StudentDetails> studentDetails = new ArrayList<StudentDetails>();

// Getters and Setters

And then removed the private Student student; property from Model Class: StudentDetails. So now it looks like this:

Model Class : StudentDetails

@Entity
@Table(name = "studentDetails")
public class StudentDetails {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer studentDetailsId;
private String FatherName;
private String MotherName;

// Getters and Setters

The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM