I would like to sovle this problec, cause it's looks interesting, to get grouped objects directly from box
I have db sheme about this:
Teacher
-id
-name
Group
-id
-name
Subject
-id
-name
Several teachers can teaches one subject
Subject_teachers
-subject_id
-teacher_id
Group_subjects
-group_id
-subject_id
I would to get grouped lessons by groups for teacher
class Teacher{
#Id id ,
...
#ManyToMany
???
Map<Group,Subject) subjects;
};
#Entity
#Table(name = "Teacher")
public class Teacher {
private Integer teacherId;
private String name;
private Set<SubjectTeachers> subjectTeachers = new HashSet<SubjectTeachers>(0);
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "teacher_id", unique = true, nullable = false)
public Integer getTeacherId() {
return teacherId;
}
public void setTeacherId(Integer teacherId) {
this.teacherId = teacherId;
}
#Column(name = "name", nullable = false)
public String getName() {
return name;
}
public void setTitle(String name) {
this.name = name;
}
#OneToMany(mappedBy = "subjectTeachers", cascade = CascadeType.ALL, fetch=FetchType.LAZY)
public Set<SubjectTeachers> getSubjectTeachers() {
return subjectTeachers;
}
public void setProjectTags(Set<SubjectTeachers> subjectTeachers) {
this.subjectTeachers = subjectTeachers;
}
}
#Entity
#Table(name = "Subject")
public class Subject{
private Integer subjectId;
private String name;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "subject_id", unique = true, nullable = false)
public Integer getSubjectId() {
return subjectId;
}
public void setSubjectId(Integer subjectId) {
this.subjectId = subjectId;
}
#Column(name = "name", nullable = false)
public String getName() {
return name;
}
public void setTitle(String name) {
this.name = name;
}
}
#Entity
#Table(name ="subject_teachers")
public SubjectTeachers{
private Integer subjectTeachersID;
private Teacher teacher;
private Subject subject;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "subjectTeachersID", unique = true, nullable = false)
public Integer getSubjectTeachersId() {
return subjectTeachersID;
}
public void setSubjectTeachersId(Integer subjectTeachersID) {
this.subjectTeachersID = subjectTeachersID;
}
#ManyToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
#JoinColumn(name = "teacher_id", nullable = false)
public Teacher getTeacher() {
return teacher;
}
public void setTeacher(Teacher teacher) {
this.teacher = teacher;
}
#OneToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
#JoinColumn(name = "subject_id", nullable = false)
public Subject getSubject() {
return subject;
}
public void setSubject(Subject subject) {
this.subject = subject;
}
}
#Entity
#Table(name = "group_subjects")
public class GroupSubjects{
private Integer groupId;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "group_id", unique = true, nullable = false)
public Integer getGroupId() {
return groupId;
}
public void setGroupId(Integer groupId) {
this.groupId = groupId;
}
private Subject subject;
#ManyToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
#JoinColumn(name = "subject_id", nullable = false)
public Subject getSubject() {
return subject;
}
public void setSubject(Subject subject) {
this.subject = subject;
}
}
Hope its help to you..
Related
I have used spring boot with hibernate. And swagger to generate the dtos and the api interface.
There are two entities. The project entity is the parent and application entity is the child. Have create a onetomany relationship. But when i try to persist. I see not applications getting added for a project.
Project Entity:
#Entity
#Table(name="ProjectEntity")
public class ProjectEntity {
#Id
#Column(name = "ProjectGuid", length = 36, nullable = false, unique = true)
#GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;
#Column(name = "Name")
private String name;
#OneToMany(mappedBy="projectApp", cascade = CascadeType.ALL)
private List<ApplicationEntity> apps=new ArrayList<>();
public ProjectEntity() {
}
public ProjectEntity(Long id, String name) {
this.id = id;
this.name = name;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public List<ApplicationEntity> getApps() {
return apps;
}
public void setApps(List<ApplicationEntity> apps) {
this.apps = apps;
}
}
Application Entity:
#Entity
#Table(name="ApplicationEntity")
public class ApplicationEntity {
#Id
#Column(name = "Name", length = 36, nullable = false, unique = true)
private String name;
private String repositoryUrl;
#ManyToOne
#Cascade(org.hibernate.annotations.CascadeType.SAVE_UPDATE)
#JoinColumn(name = "ProjectGuid")
private ProjectEntity projectApp;
public ApplicationEntity() {
}
public ApplicationEntity(String name, String repositoryUrl) {
this.name = name;
this.repositoryUrl = repositoryUrl;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getRepositoryUrl() {
return repositoryUrl;
}
public void setRepositoryUrl(String repositoryUrl) {
this.repositoryUrl = repositoryUrl;
}
public ProjectEntity getProjectApp() {
return projectApp;
}
public void setProjectApp(ProjectEntity projectApp) {
this.projectApp = projectApp;
}
}
Controller operation:
ProjectEntity project = projectService.getProject(projectName);
List<ApplicationEntity> appList = new ArrayList<>();
ApplicationEntity appEntity = new ApplicationEntity(app.getName(), app.getRepositoryUrl());
applicationRepository.save(appEntity);
appList.add(appEntity);
project.setApps(appList);
projectRepository.save(project);
You need to set the id of the ProjectEntity on the owning side (which is the ApplicationEntity)
appEntity.setProjectApp(project);
Otherwise hibernate (and your database) does not know to which parent a ApplicationEntity belongs.
Here is an example many to one relation with spring data jpa :
#Data
#MappedSuperclass
public class BaseEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
}
#Data
#Entity
public class Question extends BaseEntity{
private String questionText;
private int anketId;
private int subjectId;
#OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, orphanRemoval = true, mappedBy = "question")
List<Answer> answers;
}
#Data
#Entity
public class Answer extends BaseEntity{
private String answerText;
private String code;
private int score;
private int priority;
private boolean isValidAnswer;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "question_id", referencedColumnName = "id", insertable = false, updatable = false)
private Question question;
}
#DataJpaTest
public class QuestionRepositoryTest {
#Autowired
TestEntityManager entityManager;
#Autowired
QuestionRepository sut;
#Test
public void it_should_create_question_wiht_answers() {
Question question = new Question();
question.setSubjectId(1);
question.setAnketId(1);
question.setQuestionText("test question");
Answer answer = new Answer();
answer.setAnswerText("answer");
answer.setCode("1a");
answer.setPriority(0);
answer.setValidAnswer(true);
question.setAnswers(Arrays.asList(answer));
entityManager.persistAndFlush(question);
List<Question> questionList = sut.findAll();
assertThat(questionList).containsExactly(question);
assertThat(questionList.get(0).getAnswers().size()).isGreaterThan(0);
}
}
I am new in Hibernate association mapping. When I tried to implement a small mapping logic all the previous foreign key is automatically update to Null
File Employee.java
#Entity
public class Employee extends CommonFields implements Serializable {
private static final long serialVersionUID = -723583058586873479L;
#Id
#Column(name = "id", insertable = false, updatable = false)
#GeneratedValue
private Long id;
private String employeeName;
#OneToMany(cascade = {CascadeType.ALL}, fetch = FetchType.LAZY)
#JoinColumn(name = "emp_id", referencedColumnName = "id")
private List<Education> education;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getEmployeeName() {
return employeeName;
}
public void setEmployeeName(String employeeName) {
this.employeeName = employeeName;
}
public List<Education> getEducation() {
return education;
}
public void setEducation(List<Education> education) {
this.education = education;
}
}
File Education.java
#Entity
public class Education extends CommonFields implements Serializable {
public Education() {
}
private static final long serialVersionUID = -723583058586873479L;
#Id
#Column(name = "id", insertable = false, updatable = false)
#GeneratedValue
private Long id;
private String course;
#ManyToOne
#JoinColumn(name = "emp_id")
private Employee employee;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getCourse() {
return course;
}
public void setCourse(String course) {
this.course = course;
}
public Employee getEmployee() {
return employee;
}
public void setEmployee(Employee employee) {
this.employee = employee;
}
}
Please anyone suggest a solution. I really stuck on this part last two days.
I have 2 tables I want to join on PK and FK in JPA, but the PK is upper case and the FK lower case.
How do I map case insensitive association between Person -> GroupAssociationEntity?
My current mapping is not working.
#Entity
public class Person {
#Id
#Column(name = "id", columnDefinition = "nvarchar")
private String id;
#OneToMany(mappedBy = "person")
private List<GroupAssociationEntity> groups;
}
#Entity
#IdClass(GroupAssociationKey.class)
public class GroupAssociationEntity {
#Id
private String id;
#Id
private String memberOf;
#ManyToOne
#JoinColumn(name = "id", updatable = false, insertable = false, referencedColumnName = "id")
private Group group;
#ManyToOne
#JoinColumn(name = "memberOf", updatable = false, insertable = false, referencedColumnName = "id")
private Person person;
....
}
#Entity
public class Group {
#Id
#Column(name = "id")
private String id;
#OneToMany(mappedBy = "group")
private List<GroupAssociationEntity> persons;
......
}
I switched your mapping to:
#Entity(name = "Person")
public static class Person {
#Id
#Column(name = "id")
private String id;
#OneToMany(mappedBy = "person")
private List<GroupAssociationEntity> groups;
}
#Entity(name = "GroupAssociationEntity")
public static class GroupAssociationEntity {
#EmbeddedId
private GroupAssociationKey id;
#ManyToOne
#MapsId("id")
private Group group;
#ManyToOne
#MapsId("memberOf")
private Person person;
}
#Embeddable
public static class GroupAssociationKey implements Serializable{
private String id;
private String memberOf;
public GroupAssociationKey() {
}
public GroupAssociationKey(String id, String memberOf) {
this.id = id;
this.memberOf = memberOf;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getMemberOf() {
return memberOf;
}
public void setMemberOf(String memberOf) {
this.memberOf = memberOf;
}
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (!(o instanceof GroupAssociationKey)) return false;
GroupAssociationKey that = (GroupAssociationKey) o;
return Objects.equals(getId(), that.getId()) &&
Objects.equals(getMemberOf(), that.getMemberOf());
}
#Override
public int hashCode() {
return Objects.hash(getId(), getMemberOf());
}
}
#Entity(name = "Group")
#Table(name = "groups")
public static class Group {
#Id
#Column(name = "id")
private String id;
#OneToMany(mappedBy = "group")
private List<GroupAssociationEntity> persons;
}
And run this test on both SQL Server and MySQL:
doInJPA( entityManager -> {
Person person1 = new Person();
person1.id = "abc1";
entityManager.persist(person1);
Person person2 = new Person();
person2.id = "abc2";
entityManager.persist(person2);
Group group = new Group();
group.id = "g1";
entityManager.persist(group);
GroupAssociationEntity p1g1 = new GroupAssociationEntity();
p1g1.id = new GroupAssociationKey("G1", "ABC1");
p1g1.group = group;
p1g1.person = person1;
entityManager.persist(p1g1);
GroupAssociationEntity p2g1 = new GroupAssociationEntity();
p2g1.id = new GroupAssociationKey( "G1", "ABC2" );
p2g1.group = group;
p2g1.person = person2;
entityManager.persist(p2g1);
} );
doInJPA( entityManager -> {
Group group = entityManager.find(Group.class, "g1");
assertEquals(2, group.persons.size());
} );
doInJPA( entityManager -> {
Person person = entityManager.find(Person.class, "abc1");
assertEquals(1, person.groups.size());
} );
And it works just fine. Check it out on GitHub.
#Entity
public class Person {
#Id
#Column(name = "id", columnDefinition = "nvarchar")
private String id;
}
#Entity
#IdClass(GroupAssociationKey.class)
public class GroupAssociationEntity {
#Id
private String id;
#Id
private String memberOf;
#ManyToOne
#JoinColumn(name = "id", updatable = false, insertable = false, referencedColumnName = "id")
private Group group;
#ManyToOne
#JoinColumn(name = "id", updatable = false, insertable = false, referencedColumnName = "id")
private Person person;
....
}
#Entity
public class Group {
#Id
#Column(name = "id")
private String id;
}
try this.
I'm new to JPA and getting this error when trying to set UserContact Entity.
Caused by: org.hibernate.MappingException: Could not determine type for: java.util.Set, at table: USER_ID, for columns: [org.hibernate.mapping.Column(userContact)]
I have 2 Entity Classes and one #Embeddable class for composite key. There seems to be many solutions to this problem so I've mixed and matched attributes along getters/setters and fields. I've tried #JsonBackReference and #JsonManagedReference, #ElementCollection and other annotations. Using #Access(AccessType.PROPERTY) did start the server correctly but gave me this error when trying to perform db operation.
org.codehaus.jackson.map.JsonMappingException: failed to lazily initialize a collection of role:
Any help would be appreciated. Here are my Entities.
User
#Entity
#Table(name = "USER_RECORD")
public class User {
private UserRecordId id;
private String name;
private String address;
#Column
#ElementCollection(targetClass=UserContact.class)
private Set<UserContact> userContact = new HashSet<UserContact>(0);
#EmbeddedId
#AttributeOverrides({
#AttributeOverride(name = "userId", column = #Column(name = "USER_ID", nullable = false)),
#AttributeOverride(name = "userId2", column = #Column(name = "USER_ID2", nullable = false)) })
public UserRecordId getId() {
return this.id;
}
public void setId(UserRecordId id) {
this.id = id;
}
#OneToMany(fetch = FetchType.EAGER, mappedBy = "user")
public Set<UserContact> getUserContact() {
return this.userContact;
}
public void setUserContact(Set<UserContact> userContact) {
this.userContact = userContact;
}
#Column(name = "USER_NAME", nullable = false)
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
#Column(name = "USER_ADDRESS", nullable = false)
public String getAddress() {
return this.address;
}
public void setAddress(String address) {
this.address = address;
}
UserContact
#Entity
#Table(name = "USER_CONTACT")
public class UserContact {
private String userContactId;
private String name;
private String country;
private User user;
#Id
#Column(name = "USER_CONTACT_ID", unique = true, nullable = false)
public String getUserContactId() {
return this.userContactId;
}
public void setUserContactId(String userContactId) {
this.userContactId = userContactId;
}
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumns({
#JoinColumn(name = "USER_ID", referencedColumnName = "USER_ID"),
#JoinColumn(name = "USER_ID2", referencedColumnName = "USER_ID2") })
public User getUser() {
return this.user;
}
public void setUser(User user) {
this.user = user;
}
#Column(name = "CONTACT_NAME", nullable = false)
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
#Column(name = "CONTACT_COUNTRY", nullable = false)
public String getCountry() {
return this.country;
}
public void setCountry(String country) {
this.country = country;
}
UserRecordId/Embeddable
#Embeddable
public class UserRecordId
private String userId;
private String userId2;
#Column(name = "USER_ID", nullable = false)
public String getUserId() {
return this.userId;
}
.../////getUserid2
......
.....
override equals & hash code
You seem to have annotated a field AND a getter (userContact). You should use either FIELD or PROPERTY access but not both (particularly for the same field!).
Also you have annotated it once as ElementCollection and once as OneToMany. Can't be both, and certainly can't be ElementCollection when the element is an Entity.
I try to gather statistics of visitors for two services. It consists of daily visitors statistics and overall record. Each service can be accessed by different names. For example, user, admin, support etc. Each will have its own record as own statistics.
Here is my DB structure:
service_one: id, name
service_two: id, name
daily_stats: id, date, service_one_id, service_one_visitors,
service_two_id, service_two_visitors, overall_visitors
record_stats: id, service_one_id, service_one_record,
service_one_record_date, service_two_id, service_two_record,
service_two_record_date
Here are the relations between tables:
service_one --- (one to many) ---> daily_stats(service_one_id)
service_one --- (one to many) ---> record_stats(service_one_id)
service_two --- (one to many) ---> daily_stats(service_two_id)
service_two --- (one to many) ---> record_stats(service_two_id)
Mapping for service_one (the same is for service_two). Also setters were omitted in order to shorten the example:
#Entity
#Table(name = "service_one")
public class ServiceOne implements Serializable {
private int id;
private String name;
private Set<RecordStats> recordStats = new HashSet<RecordStats>(0);
private Set<DailyStats> dailyStats = new HashSet<DailyStats>(0);
public ServiceOne() {}
public ServiceOne(int id, String name) {
this.id = id;
this.name = name;
}
#Id
#GeneratedValue(strategy = IDENTITY)
#Column(name = "id", nullable = false, unique = true)
public int getId() {
return id;
}
#Column(name = "name")
public String getName() {
return name;
}
#OneToMany(fetch = LAZY, mappedBy = "service_one_id")
public Set<RecordStats> getRecordStats() {
return recordStats;
}
#OneToMany(fetch = LAZY, mappedBy = "service_one_id")
public Set<DailyStats> getDailyStats() {
return dailyStats;
}
}
daily_stats mapping:
#Entity
#Table(name = "daily_stats", uniqueConstraints = {
#UniqueConstraint(columnNames = "date")
})
public class DailyStats implements Serializable{
private int id;
private Date date;
private ServiceOne service_one_id;
private int service_one_visitors;
private ServiceTwo service_two_id;
private int service_two_visitors;
private int overall_visitors;
public DailyStats() {}
public DailyStats(DailyStats rec) {
this.id = rec.getId();
//...
}
#Id
#GeneratedValue
#Column(name = "id", nullable = false)
public int getId() {
return id;
}
#Temporal(DATE)
#Column(name = "date")
public Date getDate() {
return date;
}
#ManyToOne(fetch = LAZY)
#JoinColumn(name = "id", nullable = false)
public ServiceOne getService_one_id() {
return service_one_id;
}
#Column(name = "service_one_visitors")
public int getService_one_visitors() {
return service_one_visitors;
}
#ManyToOne(fetch = LAZY)
#JoinColumn(name = "id", nullable = false)
public ServiceTwo getService_two_id() {
return service_two_id;
}
#Column(name = "service_two_visitors")
public int getService_two_visitors() {
return service_two_visitors;
}
#Column(name = "overall_visitors")
public int getOverall_visitors() {
return overall_visitors;
}
}
record_stats mapping:
#Entity
#Table(name = "record_stats", uniqueConstraints = {
#UniqueConstraint(columnNames = "service_one_record_date"),
#UniqueConstraint(columnNames = "service_two_record_date")
})
public class RecordStats implements Serializable {
private int id;
private ServiceOne service_one_id;
private int service_one_record;
private Date service_one_rec_date;
private ServiceTwo service_two_id;
private int service_two_record;
private Date service_two_rec_date;
public RecordStats() {}
public RecordStats(RecordStats rec) {
this.id = rec.getId();
//...
}
#Id
#GeneratedValue
#Column(name = "id", nullable = false)
public int getId() {
return id;
}
#ManyToOne(fetch = LAZY)
#JoinColumn(name = "id", nullable = false)
public ServiceOne getService_one_id() {
return service_one_id;
}
#Column(name = "service_one_record")
public int getService_one_record() {
return service_one_record;
}
#Column(name = "service_one_record_date")
#Temporal(DATE)
public Date getService_one_rec_date() {
return service_one_rec_date;
}
#ManyToOne(fetch = LAZY)
#JoinColumn(name = "id", nullable = false)
public ServiceTwo getService_two_id() {
return service_two_id;
}
#Column(name = "service_two_record")
public int getService_two_record() {
return service_two_record;
}
#Column(name = "service_two_record_date")
#Temporal(DATE)
public Date getService_two_rec_date() {
return service_two_rec_date;
}
}
Trying to create new entry throws exception:
public static void main(String[] args) {
ServiceOne serviceOne = new ServiceOne();
serviceOne.setName("test");
SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
Session session = sessionFactory.openSession();
session.beginTransaction();
session.save(serviceOne);
session.getTransaction().commit();
//get records
session = sessionFactory.openSession();
session.beginTransaction();
List result = session.createQuery("from service_one").list();
for (ServiceOne o : (List<ServiceOne>)result) {
System.out.println(o.getName());
}
session.getTransaction().commit();
session.close();
}
org.hibernate.MappingException: Repeated column in mapping for entity:
VisitorsCounter.model.entity.DailyStats column: id (should be
mapped with insert="false" update="false")
What is wrong with my mapping?
It seems to me that
#JoinColumn(name = "id", nullable = false)
public ServiceOne getService_one_id() {
return service_one_id;
}
in DailyStats is wrong; you should have name = "service_one_id".
You have the same problem in getService_two_id() and in methods of same names in RecordStats.
May I also ask why don't you name the references in the classes fields serviceOne and serviceTwo instead of service_one_id and service_two_id.