Spring + Thymeleaf creates new record instead of updating - spring-mvc

Question

I am trying to update an existing record but instead, it creates a new record even though the primary key is not a null value. Also, the subject field is returning null. I'm using the CrudRepository from spring framework.
What I want to happen is for it to update in the database instead of creating, the subject field should return Math, Science, or English.
Below is my input form, controller, Entity, DTO, and service implementation.
What am I doing wrong since my other input form for users uses the same code
edit.html
<form th:method="PUT" th:action="#{~/teacher/edit}" th:object="${grades}">
<input type="hidden" name="id" th:field="*{id}">
<input type="hidden" name="studentID" th:field="*{studentID}">
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="quiz1" class="col-form-label">Quiz 1:</label></div>
<div class="col-xl-3"><input id="quiz1" type="text" th:field="*{quiz1}"></div>
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="quiz2" class="col-form-label">Quiz 2:</label></div>
<div class="col-xl-3"><input id="quiz2" type="text" th:field="*{quiz2}"></div>
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="quiz3" class="col-form-label">Quiz 3:</label></div>
<div class="col-xl-3"><input id="quiz3" type="text" th:field="*{quiz3}"></div>
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="quiz4" class="col-form-label">Quiz 4:</label></div>
<div class="col-xl-3"><input id="quiz4" type="text" th:field="*{quiz4}"></div>
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="quiz5" class="col-form-label">Quiz 5:</label></div>
<div class="col-xl-3"><input id="quiz5" type="text" th:field="*{quiz5}">
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="hw1" class="col-form-label">Homework 1:</label></div>
<div class="col-xl-3"><input id="hw1" type="text" th:field="*{hw1}"></div>
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="hw2" class="col-form-label">Homework 2:</label></div>
<div class="col-xl-3"><input id="hw2" type="text" th:field="*{hw2}"></div>
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="hw3" class="col-form-label">Homework 3:</label></div>
<div class="col-xl-3"><input id="hw3" type="text" th:field="*{hw3}"></div>
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="hw4" class="col-form-label">Homework 4:</label></div>
<div class="col-xl-3"><input id="hw4" type="text" th:field="*{hw4}"></div>
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="hw5" class="col-form-label">Homework 5:</label></div>
<div class="col-xl-3"><input id="hw5" type="text" th:field="*{hw5}"></div>
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="hw6" class="col-form-label">Homework 6:</label></div>
<div class="col-xl-3"><input id="hw6" type="text" th:field="*{hw6}"></div>
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="hw7" class="col-form-label">Homework 7:</label></div>
<div class="col-xl-3"><input id="hw7" type="text" th:field="*{hw7}"></div>
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="hw8" class="col-form-label">Homework 8:</label></div>
<div class="col-xl-3"><input id="hw8" type="text" th:field="*{hw8}"></div>
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="exam1" class="col-form-label">Midterms:</label></div>
<div class="col-xl-3"><input id="exam1" type="text" th:field="*{exam1}"></div>
</div>
<div class="row" style="padding: 10px;">
<div class="col-xl-3"></div>
<div class="col-xl-5"><label for="exam2" class="col-form-label">Finals:</label></div>
<div class="col-xl-3"><input id="exam2" type="text" th:field="*{exam2}"></div>
</div>
<div class="mb-3">
<label for="subject" class="form-label">Subject</label>
<select id="subject" th:field="*{subject}">
<option th:value="Math" th:text="Math"></option>
<option th:value="English" th:text="English"></option>
<option th:value="Science" th:text="Science"></option>
<option selected th:value=null th:text="None"></option>
</select>
</div>
<button type="submit" class="btn btn-success">Submit</button>
</div>
</form>
TeacherController
#Controller
#RequestMapping("teacher")
public class TeacherController {
#Autowired
private AdminService adminService;
#Autowired
private GradesService gradesService;
#GetMapping
public String index(Model model){
model.addAttribute("users", adminService.list());
return "teacher/teacher";
}
#GetMapping("/section")
public String section(Model model){
model.addAttribute("users", adminService.list());
return "teacher/section";
}
#GetMapping("/edit")
public String edit(Model model){
model.addAttribute("users", adminService.list());
return "teacher/viewStudents";
}
#GetMapping("/{id}")
private String getUser(#PathVariable Long id, Model model) {
model.addAttribute("user", adminService.get(id));
model.addAttribute("grades", gradesService.get(id));
return "teacher/edit";
}
#PutMapping("/edit")
private String updateUser(GradesDTO gradesDTO, Model model) {
gradesService.update(gradesDTO);
return edit(model);
}
GradesEntity
#Entity
#Table(name="grades")
public class Grades {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long Id;
#ManyToOne
#JoinColumn(name="student_ID", nullable = false)
private User studentID;
#Column
private String subject;
#Column(columnDefinition = "BIGINT default '0'")
private Long quiz1 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long quiz2 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long quiz3 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long quiz4 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long quiz5 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long hw1 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long hw2 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long hw3 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long hw4 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long hw5 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long hw6 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long hw7 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long hw8 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long exam1 = 0L;
#Column(columnDefinition = "BIGINT default '0'")
private Long exam2 = 0L;
#Column(columnDefinition = "Double default '0.0'")
private Double weightQ = 0D;
#Column(columnDefinition = "Double default '0.0'")
private Double weightD = 0D;
#Column(columnDefinition = "Double default '0.0'")
private Double weightE = 0D;
public Grades(){
}
public Grades(Long id){
this.Id = id;
}
public Grades(GradesDTO gradesDTO){
this.studentID = new User(gradesDTO.getStudentID());
this.quiz1= gradesDTO.getQuiz1();
this.quiz2= gradesDTO.getQuiz2();
this.quiz3= gradesDTO.getQuiz3();
this.quiz4= gradesDTO.getQuiz4();
this.quiz5= gradesDTO.getQuiz5();
this.hw1=gradesDTO.getHw1();
this.hw2=gradesDTO.getHw2();
this.hw3=gradesDTO.getHw3();
this.hw4=gradesDTO.getHw4();
this.hw5=gradesDTO.getHw5();
this.hw6=gradesDTO.getHw6();
this.hw7=gradesDTO.getHw7();
this.hw8=gradesDTO.getHw8();
this.exam1=gradesDTO.getExam1();
this.exam2=gradesDTO.getExam2();
this.subject = gradesDTO.getSubject();
}
public String getSubject() {
return subject;
}
public void setSubject(String subject) {
this.subject = subject;
}
public Long getId() {
return Id;
}
public void setId(Long id) {
Id = id;
}
public User getStudentID() {
return studentID;
}
public void setStudentID(User studentID) {
this.studentID = studentID;
}
public Long getQuiz1() {
return quiz1;
}
public void setQuiz1(Long quiz1) {
this.quiz1 = quiz1;
}
public Long getQuiz2() {
return quiz2;
}
public void setQuiz2(Long quiz2) {
this.quiz2 = quiz2;
}
public Long getQuiz3() {
return quiz3;
}
public void setQuiz3(Long quiz3) {
this.quiz3 = quiz3;
}
public Long getQuiz4() {
return quiz4;
}
public void setQuiz4(Long quiz4) {
this.quiz4 = quiz4;
}
public Long getQuiz5() {
return quiz5;
}
public void setQuiz5(Long quiz5) {
this.quiz5 = quiz5;
}
public Long getHw1() {
return hw1;
}
public void setHw1(Long hw1) {
this.hw1 = hw1;
}
public Long getHw2() {
return hw2;
}
public void setHw2(Long hw2) {
this.hw2 = hw2;
}
public Long getHw3() {
return hw3;
}
public void setHw3(Long hw3) {
this.hw3 = hw3;
}
public Long getHw4() {
return hw4;
}
public void setHw4(Long hw4) {
this.hw4 = hw4;
}
public Long getHw5() {
return hw5;
}
public void setHw5(Long hw5) {
this.hw5 = hw5;
}
public Long getHw6() {
return hw6;
}
public void setHw6(Long hw6) {
this.hw6 = hw6;
}
public Long getHw7() {
return hw7;
}
public void setHw7(Long hw7) {
this.hw7 = hw7;
}
public Long getHw8() {
return hw8;
}
public void setHw8(Long hw8) {
this.hw8 = hw8;
}
public Long getExam1() {
return exam1;
}
public void setExam1(Long exam1) {
this.exam1 = exam1;
}
public Long getExam2() {
return exam2;
}
public void setExam2(Long exam2) {
this.exam2 = exam2;
}
public Double getWeightQ() {
return weightQ;
}
public void setWeightQ(Double weightQ) {
this.weightQ = weightQ;
}
public Double getWeightD() {
return weightD;
}
public void setWeightD(Double weightD) {
this.weightD = weightD;
}
public Double getWeightE() {
return weightE;
}
public void setWeightE(Double weightE) {
this.weightE = weightE;
}
}
GradesDTO
public class GradesDTO {
private Long id;
private Long studentID;
private Long quiz1;
private Long quiz2;
private Long quiz3;
private Long quiz4;
private Long quiz5;
private Long hw1;
private Long hw2;
private Long hw3;
private Long hw4;
private Long hw5;
private Long hw6;
private Long hw7;
private Long hw8;
private Long exam1;
private Long exam2;
private Double weightQ;
private Double weightD;
private Double weightE;
private String subject;
public GradesDTO(){
}
public GradesDTO(Long Id, Long quiz1, Long quiz2, Long quiz3, Long quiz4, Long quiz5, Long hw1, Long hw2, Long hw3, Long hw4, Long hw5, Long hw6, Long hw7, Long hw8, Long exam1,
Long exam2, Double weightQ, Double weightD, Double weightE, String subject ){
this.id=Id;
this.quiz1=quiz1;
this.quiz2=quiz2;
this.quiz3=quiz3;
this.quiz4=quiz4;
this.quiz5=quiz5;
this.hw1=hw1;
this.hw2=hw2;
this.hw3=hw3;
this.hw4=hw4;
this.hw5=hw5;
this.hw6=hw6;
this.hw7=hw7;
this.hw8=hw8;
this.exam1=exam1;
this.exam2=exam2;
this.weightQ=weightQ;
this.weightD=weightD;
this.weightE=weightE;
this.subject=subject;
}
public GradesDTO(Grades grades){
this.id = grades.getId();
this.studentID = grades.getStudentID().getId();
this.quiz1 = grades.getQuiz1();
this.quiz2 = grades.getQuiz2();
this.quiz3 = grades.getQuiz3();
this.quiz4 = grades.getQuiz4();
this.quiz5 = grades.getQuiz5();
this.hw1 = grades.getHw1();
this.hw2 = grades.getHw2();
this.hw3 = grades.getHw3();
this.hw4 = grades.getHw4();
this.hw5 = grades.getHw5();
this.hw6 = grades.getHw6();
this.hw7 = grades.getHw7();
this.hw8 = grades.getHw8();
this.exam1 = grades.getExam1();
this.exam2 = grades.getExam2();
this.weightD = grades.getWeightD();
this.weightQ = grades.getWeightQ();
this.weightE = grades.getWeightE();
this.subject = grades.getSubject();
}
public Long getStudentID() {
return studentID;
}
public void setStudentID(Long studentID) {
this.studentID = studentID;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public Long getQuiz1() {
return quiz1;
}
public void setQuiz1(Long quiz1) {
this.quiz1 = quiz1;
}
public Long getQuiz2() {
return quiz2;
}
public void setQuiz2(Long quiz2) {
this.quiz2 = quiz2;
}
public Long getQuiz3() {
return quiz3;
}
public void setQuiz3(Long quiz3) {
this.quiz3 = quiz3;
}
public Long getQuiz4() {
return quiz4;
}
public void setQuiz4(Long quiz4) {
this.quiz4 = quiz4;
}
public Long getQuiz5() {
return quiz5;
}
public void setQuiz5(Long quiz5) {
this.quiz5 = quiz5;
}
public Long getHw1() {
return hw1;
}
public void setHw1(Long hw1) {
this.hw1 = hw1;
}
public Long getHw2() {
return hw2;
}
public void setHw2(Long hw2) {
this.hw2 = hw2;
}
public Long getHw3() {
return hw3;
}
public void setHw3(Long hw3) {
this.hw3 = hw3;
}
public Long getHw4() {
return hw4;
}
public void setHw4(Long hw4) {
this.hw4 = hw4;
}
public Long getHw5() {
return hw5;
}
public void setHw5(Long hw5) {
this.hw5 = hw5;
}
public Long getHw6() {
return hw6;
}
public void setHw6(Long hw6) {
this.hw6 = hw6;
}
public Long getHw7() {
return hw7;
}
public void setHw7(Long hw7) {
this.hw7 = hw7;
}
public Long getHw8() {
return hw8;
}
public void setHw8(Long hw8) {
this.hw8 = hw8;
}
public Long getExam1() {
return exam1;
}
public void setExam1(Long exam1) {
this.exam1 = exam1;
}
public Long getExam2() {
return exam2;
}
public void setExam2(Long exam2) {
this.exam2 = exam2;
}
public Double getWeightQ() {
return weightQ;
}
public void setWeightQ(Double weightQ) {
this.weightQ = weightQ;
}
public Double getWeightD() {
return weightD;
}
public void setWeightD(Double weightD) {
this.weightD = weightD;
}
public Double getWeightE() {
return weightE;
}
public void setWeightE(Double weightE) {
this.weightE = weightE;
}
public String getSubject() {
return subject;
}
public void setSubjectId(String subject) {
this.subject = subject;
}
}
GradesServiceImpl
#Service
public class GradesServiceImpl implements GradesService {
#Autowired
private GradesRepository gradesRepository;
#Autowired
AdminRepository adminRepository;
#Autowired
AdminServiceImpl adminServiceimpl;
#Override
public List<GradesDTO> list() {
return StreamSupport.stream(gradesRepository.findAll().spliterator(), false)
.map(GradesDTO::new)
.collect(Collectors.toList());
}
#Override
public void add(GradesDTO user) {
gradesRepository.save(new Grades(user));
}
#Override
public GradesDTO get(Long id) {
AdminDTO adminDTO = adminServiceimpl.get(id);
User user = new User(adminDTO);
return new GradesDTO(gradesRepository.findById(gradesRepository.findByStudentID(user).getId()).get());
}
#Override
public void update(GradesDTO updatedUser) {
Grades grades = new Grades(updatedUser);
gradesRepository.save(grades);
}
}

Answer 1

You are not correctly updating the record in the database. As per your code
#Override
public void update(GradesDTO updatedUser) {
Grades grades = new Grades(updatedUser);
gradesRepository.save(grades);
}
You are just trying to save new record into the table, as JPA is not aware about anything weather it already exists or not. Hence, everytime you are trying it saving a new record.
To properly update any record you need to first find it/fetch it from the database then do the modification into the fetched entity object.
Now either you can call save method on it or not , it will get saved automatically by JPA.
#Override
public void update(GradesDTO updatedUser) {
Grades recordToBeUpdated= gradesRepository.findById(pass_your_id_here);
//You can find your record which you want to update by any means ,Id is not neccesary.
//do the update on the fetched entity obbject
//recordToBeUpdated--> set new values
gradesRepository.save(recordToBeUpdated);
}