I have problem with saving data in join table in many to many relation. I have 2 model classes:employee and task. When Im assinging new task to employee it is not saving in the employees_task table, only Id of task is changing in choosen employee. This is how looks table generated by Spring.
Im assigning tasks with this method in TaskController:
#RequestMapping(value = "/task/assign/{taskId}")
public String assignTask(#PathVariable("taskId")Integer id, #ModelAttribute Employee employee){
Task task = tasksService.getTaskById(id);
employee.addTask(task);
employeeService.save(employee);
return "redirect:/employees";
}
Im saving data to database with JPARepository Interface.
Employee class:
#Entity(name = "employees")
public class Employee{
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "employee_id")
private int id;
#NotEmpty
#NotNull
#Size(min = 3, max = 30)
private String name;
#NotEmpty
#NotNull
#Size(min = 3, max = 30)
private String surname;
#ManyToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
#JoinTable(
name = "employees_tasks",
joinColumns = #JoinColumn(name = "employee_id"),
inverseJoinColumns = #JoinColumn(name = "task_id")
)
private Set<Task> tasks = new HashSet<>();
#OneToOne
private User user;
public void addTask(Task task) {
this.tasks.add(task);
task.getEmployees().add(this);
}
//constructors,setters,getters
}
Task class:
#Entity(name = "tasks")
public class Task{
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "task_id")
private int id;
private String title;
private String description;
private int numberOfLeftContractors;
#ManyToMany(mappedBy = "tasks",cascade = CascadeType.ALL, fetch = FetchType.LAZY)
private Set<Employee> employees = new HashSet<>();;
#ManyToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
#JoinTable(
name = "employees_tasks",
joinColumns = #JoinColumn(name = "employee_id"),
inverseJoinColumns = #JoinColumn(name = "task_id")
)
private Set<Task> tasks;
public void addTask(Task task) {
if(tasks==null) {
tasks=new HashSet<task>();
}
tasks.add(task);
}
Related
I have next classes:
#Entity
#Table
public class Lesson implements ModelEntity {
#Id
#Column(name = "lesson_id")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "course_id")
private Course course;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "lesson_type_id")
private LessonType lessonType;
private LocalDate date;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "time_slot_id")
private TimeSlot timeSlot;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "auditorium_id")
private Auditorium auditorium;
#ManyToMany(fetch = FetchType.LAZY)
#JoinTable(name = "lesson_teacher", joinColumns = #JoinColumn(name = "lesson_id"), inverseJoinColumns = #JoinColumn(name = "person_id"))
private Set<Teacher> teachers = new HashSet<>();;
#ManyToMany(fetch = FetchType.LAZY)
#JoinTable(name = "lesson_group", joinColumns = #JoinColumn(name = "lesson_id"), inverseJoinColumns = #JoinColumn(name = "group_id"))
private Set<Group> groups = new HashSet<>();
}
#Entity
#Table(name = "groups")
public class Group implements ModelEntity {
#Id
#Column(name = "group_id")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
#Column(name = "group_name")
private String name;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "faculty_id")
private Faculty faculty;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "group")
private List<Student> students;
}
#Entity
#Table
public class TimeSlot implements ModelEntity {
#Id
#Column(name = "time_slot_id")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
#Column(name = "time_slot_number")
private Integer number;
#Column(name = "time_slot_name")
private String name;
#Column(name = "time_slot_start")
private LocalTime startTime;
#Column(name = "time_slot_end")
private LocalTime endTime;
}
I wrote method, that find all Groups_id by Date and TimeSlot_id not connected to Lesson with CriteriaBuilder API, it works perfect:
#Override
public Set<Integer> getBusyGroupsId(int lessonId, LocalDate date, int timeSlotId) {
logger.debug("getBusyGroupsId() with agruments {}, {}, {}.", lessonId, date, timeSlotId);
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery<Integer> query = criteriaBuilder.createQuery(Integer.class);
Root<Lesson> root = query.from(Lesson.class);
List<Predicate> predicates = new ArrayList<>();
Join<Lesson, TimeSlot> timeSlotJoin = root.join("timeSlot", JoinType.LEFT);
predicates.add(criteriaBuilder.equal(timeSlotJoin.get("id"), timeSlotId));
predicates.add(criteriaBuilder.equal(root.get("date"), date));
if (nonNull(lessonId)) {
predicates.add(criteriaBuilder.notEqual(root.get("id"), lessonId));
}
query.where(predicates.toArray(new Predicate[] {}));
SetJoin<Lesson, Group> joinGroup = root.joinSet("groups");
query.multiselect(joinGroup.get("id"));
TypedQuery<Integer> result = entityManager.createQuery(query);
return result.getResultStream().collect(Collectors.toSet());
}
But after that I think- what about JPA, can it be easier?
I tried something like that, but it doesnt work:
public Set<Integer> findGroupIdByIdNotAndDateEqualsAndTimeSlotIdEquals(Integer lessonId, LocalDate date, Integer timeSlotId);
How to fix it?
Also I stacked with writing method with JPA that should find all Lesson by Group_id and Date(or startDate-endDate) and sort it: first by date, second- by TimeSlot_number.
Can it be written with JPA?
Thanks in advance.
Don't throw stones, I'm just getting to know Spring JPA.
I'm new with Hibernate and Criteria Query.
How can I implement it with Hibernate Criteria Object?
SELECT stateslocalization.StateId, stateslocalization.localization AS name
FROM processstate
Join states ON states.id = processstate.StateId
JOIN stateslocalization ON stateslocalization.StateId = states.id
WHERE processstate.ProcessId = 38 and processstate.StateId = states.id AND stateslocalization.StateId = states.id
Entities:
Process:
#Entity
#Table(name = "processes")
public class Process {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private int id;
private String name;
#ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.PERSIST)
#JoinTable(
name = "processstate",
joinColumns = {#JoinColumn(name = "ProcessId")},
inverseJoinColumns = {#JoinColumn(name = "StateId")}
)
private Set<State> states;
//getters and setters.....
}
State:
#Entity
#Table(name = "states")
public class State {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "id")
private int id;
private String name;
#ManyToMany(mappedBy = "states", cascade = CascadeType.PERSIST, fetch = FetchType.EAGER)
private Set<Process> processes;
#OneToOne(mappedBy = "state")
private StateLocalization stateLocalization;
//getters and setters.....
}
StateLocalization:
#Entity
#Table(name = "stateslocalization")
public class StateLocalization {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private int id;
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "StateId", referencedColumnName = "id")
private State state;
private String localization;
//getters and setters.....
}
I did it with native query but I don't know how I can implement it to Hibernate Criteria, because I don't have entity processstate (it's only table).
I have two table in relation many to many
public class Repertoire {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(nullable = false, unique = true)
private Integer id;
private String name;
private Integer dayWeek;
#ManyToMany(cascade = CascadeType.REMOVE)
#JoinTable(
name = "repertoire_seance",
joinColumns = { #JoinColumn(name = "repertoire_id")},
inverseJoinColumns = {#JoinColumn(name = "seance_id")}
)
List<Seance> seances = new ArrayList<>();
}
and
public class Seance {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(nullable = false, unique = true)
private Integer id;
private java.time.LocalTime displayTime;
#ManyToOne
private Film film;
#Column(length=127)
private String kind;
#ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.MERGE)
private Hall hall;
#OneToMany(mappedBy = "reservationSeance")
#JsonIgnore
private List<Reservation> reservations = new ArrayList<>();
}
Hibernate create linked tabel repertoire_seance is posible get seances by seancesId and repertoire.dayWeek using spring data (JpaRepository) something like that findBySeanceIdAndRepertoireDayWeek()?
You could achieve this by writing an HQL.
It would look something like this:
select s from Repertoire r inner join r.seances s where r.dayWeek ="Your Value" and s.id = "Your Id Value"
I am facing a hibernate problem in updainting the join table in one to many mapping with hibernate. Below are my two entity class and join table entity class.
ArticleCategoryMap.java
#Entity
#Table(name = "ARTICLECATEGORYMAP")
public class ArticleCategoryMap {
private static final long serialVersionUID = -5653708523600543988L;
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE)
#Column ( name = "id")
Long id;
#ManyToOne(targetEntity = Article.class, fetch = FetchType.EAGER, optional = true, cascade = CascadeType.PERSIST)
#JoinColumn(name = "ARTICLE_ID", nullable = true, insertable = true, updatable = true)
private Article article;
#ManyToOne(targetEntity = Category.class, fetch = FetchType.EAGER, optional = true, cascade = CascadeType.PERSIST)
#JoinColumn(name = "CATEGORY_ID", nullable = true, insertable = true, updatable = true)
private Category category;
//setter and getter
}
Article.java
#Entity
#Table(name = "ARTICLE")
public class Article {
private long id;
private String title;
private String description;
private String keywords;
private String content;
#Id
#GeneratedValue
#Column(name = "ARTICLE_ID")
public long getId() {
return id;
}
//setter and getter
}
Category.java
#Entity
#Table(name = "CATEGORY")
public class Category {
private long id;
private String name;
#OneToMany(cascade = CascadeType.ALL, fetch=FetchType.EAGER)
#JoinTable(
name = "ARTICLECATEGORYMAP",
joinColumns = #JoinColumn(name = "CATEGORY_ID"),
inverseJoinColumns = #JoinColumn(name = "ARTICLE_ID")
)
#CollectionId(
columns = #Column(name="id"),
type=#Type(type="long"),
generator = "sequence"
)
private Collection<Article> articles;
#Id
#GeneratedValue
#Column(name = "CATEGORY_ID")
public long getId() {
return id;
}
#OneToMany(cascade = CascadeType.ALL, fetch=FetchType.EAGER)
#JoinTable(
name = "ARTICLECATEGORYMAP",
joinColumns = #JoinColumn(name = "CATEGORY_ID"),
inverseJoinColumns = #JoinColumn(name = "ARTICLE_ID")
)
#CollectionId(
columns = #Column(name="id"),
type=#Type(type="long"),
generator = "sequence"
)
// setter an getter
}
Now suppose first time I have 2 elements in article table which is mapping to one entry of the category table. so the join table will look something like
Now due to some reason, I want to update the entry where the article entry will map to a new category ID. So the final DB should look like
So My problem Is how can I update this join table.
If you want one to many relationship (1 category have many articles and 1 article to 1 category) you dont need a join table.
The entity classes should look like that:
Category Entity:
Contains a Set of articles:
#Entity
#Table(name = "CATEGORY")
public class Category {
private long id;
private String name;
#OneToMany(mappedBy="category")
private Set<Article> articles;
......
}
Article Entity:
#Entity
#Table(name = "ARTICLE")
public class Article {
#ManyToOne
#JoinColumn(name="id", nullable=false)
private Category category;
private long id;
private String title;
private String description;
private String keywords;
private String content;
.......
}
For more details take a look at hibernate-one-to-many. Hope this helps.
Also move annotation from methods to fields. This:
private long id;
#Id
#GeneratedValue
#Column(name = "CATEGORY_ID")
public long getId() {
return id;
}
Should be:
#Id
#GeneratedValue
#Column(name = "CATEGORY_ID")
private long id;
public long getId() {
return id;
}
Many to many relationship:
At your database you have 3 tables:
CATEGORY
ARTICLE
ARTICLECATEGORYMAP (join table)
For many to many relationship entities would be:
Category Entity:
#Entity
#Table(name = "CATEGORY")
public class Category {
#Id
#GeneratedValue
#Column(name = "CATEGORY_ID")
private long id;
private String name;
#ManyToMany(cascade = { CascadeType.ALL })
#JoinTable(
name = "ARTICLECATEGORYMAP",
joinColumns = { #JoinColumn(name = "CATEGORY_ID") },
inverseJoinColumns = { #JoinColumn(name = "ARTICLE_ID") }
)
Set<Article > articles = new HashSet<>();
.....
}
Article Entity:
#Entity
#Table(name = "ARTICLE")
public class Article {
#Id
#GeneratedValue
#Column(name = "ARTICLE_ID")
private long id;
private String title;
private String description;
private String keywords;
private String content;
#ManyToMany(mappedBy = "articles")
private Set<Category> categories = new HashSet<>();
.......
}
For more info take a look at many-to-many ralationship
I have entities as below. I need to retrieve list of CIDs from CEntity using AEntity's id;
I have to traverse thru AEntity -> ABMapping -> BEntity -> fetch CID from CEntity.
Is there a way to achieve this in JPA or Should I go native query way joining all four tables and get CIDs from CEntity?
Entity A
#Entity
public class AEntity {
#Id
private long id;
#ManyToMany
#JoinTable(name = "ABMapping", joinColumns = #JoinColumn(name = "AEntity_ref", referencedColumnName = "id"), inverseJoinColumns = #JoinColumn(name = "BEntity_ref", referencedColumnName = "id"))
private List<BEntity> bEntities = new ArrayList<>();
}
Entity B
#Entity
public class BEntity {
#Id
private long id;
private CEntity cEntity;
#ManyToMany(mappedBy = "bEntities")
private List<AEntity> aEntities;
#ManyToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "cEntityId")
public CEntity getCEntity() {
return cEntity;
}
}
Entity ABMapping
#Entity
public class ABMapping {
#Id
private long id;
#Column(name="AEntity_ref")
private long ARefId;
#Column(name = "BEntity_ref")
private long BRefId;
}
Entity C
#Entity
public class CEntity {
#Id
private long id;
private String CID;
private List<BEntity> bEntity;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "c", cascade =
CascadeType.ALL)
public List<BEntity> getBEntities() {
return bEntity;
}
#Column(name = "CID_column")
public String getCId() {
return CID;
}
public void setCId(String CID) {
this.CID = CID;
}
}
I went with what #JB Nizet has suggested with.
select distinct c from AEntity a join a.bEntities b join b.cEntity c where a.id = :id