休眠加入兩張表

Question

我正在學習Spring和Hibernate。我有以下形式

在我的數據庫表中插入表單值後，我希望他們看起來像以下：

表名：學生

student_id studentName 
    1.   Jason Stathum 

表名：studentdetails

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

但是當我真正在我的數據庫插入值，該studentdetails表看起來像下面

表名：studentdetails

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

正如你所看到的一切完美的作品，但只有student_id列沒有按不會被填滿。你能告訴我我做錯了什麼嗎？

這裏的是我的代碼：

模型類：學生

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 

模型類：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 

控制器

@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頁：表

<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(); 
} 

Answer 1

刪除從StudentDetails的student屬性@JoinColumn註釋應該可以解決這個問題：

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

Answer 2

更改此片段：

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

到：

@ManyToOne 
private Student student; 

，這應該工作。

Answer 3

我設法解決了這個問題，我希望這有助於他人。 我在

模型類做了一些改變：學生

@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 

，然後取出從模型類的private Student student;屬性：StudentDetails。所以，現在它看起來像這樣：

模型類：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