Hi I am new to this world.
I am making my own application with spring jpa hibernate.
I have an entity class. It works generally but it duplicates attributes.
My code look like this:
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.validation.constraints.NotNull;
#Entity
public class Event {
#Id
#GeneratedValue
private Integer id;
public Integer getId() {
return id;
}
#Column(nullable = false)
public void setId(Integer id) {
this.id = id;
}
/*------------------------------ title ------------------------*/
private String title;
#Column(nullable = false)
public String getTitle() {
return title;
}
#Column(nullable = false)
public void setTitle(String title) {
this.title = title;
}
/* [Note] I have two extra ids : event_id, eventId
- so these are not the case of the duplication. */
/*------------------- event_id -----------------------------*/
private String event_id;
public String getEvent_id() {
return event_id;
}
public void setEvent_id(String event_id) {
this.event_id = event_id;
}
/*-------------- eventId -------------------------------------*/
#Column(unique = true)
private String eventId;
public String getEventId() {
return eventId;
}
public void setEventId(String eventId) {
this.eventId = eventId;
}
/*------------------------------ publishedDate ------------------------------------------*/
private String publishedDate;
public String getPublishedDate() {
return publishedDate;
}
#Column(nullable = false)
public void setPublishedDate(String publishedDate) {
this.publishedDate = publishedDate;
}
/*--------------------------------- endTime -----------------------------------*/
private String endTime;
public String getEndTime() {
return endTime;
}
#Column(nullable = false)
public void setEndTime(String endTime) {
this.endTime = endTime;
}
/*-------------------------------- user ------------------------------------------*/
#ManyToOne
#JoinColumn(name="user_id")
private User user;
public User getUser() {
return user;
}
#Column(nullable = false)
public void setUser(User user) {
this.user = user;
}
Then when I check JPA diagram, it has duplication of several attributes.
I added my JPA diagram image(the red parts are duplicated)
This is my very first application with java programming.
so please understand, even I read documentation of the spring jpa,
It is difficult to figure out what exactly I did wrong in the code.
Any ideas? Thanks in advance.
The problem is that JPA expects either field level annotations or accessor (getters/setters) annotations. However you are using both, which basically isn't allowed. Remove all he annotations from the accessors and only put them on the fields.
Small hint on Java programming (styling) put your fields on top of the classes instead of between the accessors.
#Entity
public class Event {
#Id
#GeneratedValue
private Integer id;
#Column(unique = true)
private String eventId;
private String event_id;
#Column(nullable = false)
private String title;
#Column(nullable = false)
private String publishedDate;
#Column(nullable = false)
private String endTime;
#ManyToOne
#JoinColumn(name="user_id")
#Column(nullable = false)
private User user;
// Getters / Setters omitted
}
Remove the annotations from the accessors, also do you really want to set the id? I would expect not, so you might want to remove the setId method.
As mentioned in comments, your problem is that you are using two annotations for the same attribute, first in the field and then in its getter/setter, so you have to use only one of them, for example:
#Id
#GeneratedValue
private Integer id;
public Integer getId() {
return id;
}
#Column(nullable = false)
public void setId(Integer id) {
this.id = id;
}
Should be:
#Id
#GeneratedValue
private Integer id;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
And it's wrong to usnnotations here with both getter and setter:
#Column(nullable = false)
public String getTitle() {
return title;
}
#Column(nullable = false)
public void setTitle(String title) {
this.title = title;
}
Note:
So in order to avoid this, you have to choose between:
Using annotations with the field.
And using them with its setter.
Spring Boot 2.0.0.M5, JPA, Hibernate 5.2.11.Final
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "auto_gen")
#SequenceGenerator(name = "auto_gen", sequenceName = "customer_id_seq", allocationSize=1)
#Column(name = "id")
private Long id;
This is a working sample:
package hello;
import org.hibernate.annotations.Type;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.SequenceGenerator;
import javax.persistence.Table;
#Entity
#Table(name = "customer")
public class Customer {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "auto_gen")
#SequenceGenerator(name = "auto_gen", sequenceName = "customer_id_seq", allocationSize = 1)
#Column(name = "id")
private Long id;
#Column(name = "first_name")
//#Type(type="org.hibernate.type.StringType")
private String firstName;
#Column(name = "last_name")
//#Type(type="org.hibernate.type.StringType")
private String lastName;
protected Customer() {
}
public Customer(String firstName, String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
#Override
public String toString() {
return String.format("Customer[id=%d, firstName='%s', lastName='%s']", id, firstName, lastName);
}
}
Related
I know there are similar questions here, but for some reason they just don't work for me. Here, I can't even find which column is repeated. The basic idea of the system is that using a join on deptId (FK), I can get all the employees in a certain department.
I have reproduced below the relevant code:
Employee.java
package com.tvlk.advDemo.model;
import javax.persistence.*;
import javax.swing.*;
import java.io.Serializable;
#Entity
#Table(name="employees")
public class Employee implements Serializable {
private long id;
private String name;
private String designation;
private long deptId;
private Department department;
public Employee() {
}
public Employee(String name, String designation, long deptId) {
this.name = name;
this.designation = designation;
this.deptId = deptId;
}
#Id
#GeneratedValue
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
#Column(name = "name", nullable = false)
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
#Column(name = "designation", nullable = false)
public String getDesignation() {
return designation;
}
public void setDesignation(String designation) {
this.designation = designation;
}
// #Column(name = "deptId", nullable = false)
public long getDeptId() {
return deptId;
}
public void setDeptId(long deptId) {
this.deptId = deptId;
}
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "deptId", nullable = false)
public Department getDepartment() {
return department;
}
public void setDepartment(Department department){
this.department = department;
}
#Override
public String toString() {
return "Employee [id=" + id + ", name=" + name + ", designation=" + designation + ", deptId=" + deptId
+ "]";
}
}
Here is Department.java
package com.tvlk.advDemo.model;
import javax.persistence.*;
import java.io.Serializable;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
#Entity
#Table(name="departments")
public class Department implements Serializable {
private long id;
private String deptName;
private String deptHead;
private long budget;
private List<Employee> employees;
public Department(){
}
public Department(long id, String deptName, String deptHead, long budget)
{
this.id = id;
this.deptHead = deptHead;
this.deptName = deptName;
this.budget = budget;
}
#Id
public long getId() {return id;}
public void setId(long id) {this.id = id; }
#Column(name = "name", nullable = false)
public String getDeptName(){return deptName;}
public void setDeptName(String deptName){this.deptName = deptName; }
#Column(name = "deptHead", nullable = false)
public String getDeptHead(){return deptHead; }
public void setDeptHead(String deptHead){this.deptHead = deptHead; }
#Column(name = "budget", nullable = false)
public long getBudget(){return budget;}
public void setBudget(long budget){this.budget = budget; }
#OneToMany(fetch = FetchType.LAZY, mappedBy = "id", targetEntity = Employee.class)
public List<Employee> getEmployees() {
return this.employees;
}
public void setEmployees(List<Employee> employees) {
this.employees = employees;
}
}
Any help will be appreciated, I am quite new to springboot and hibernate. Note that I am making REST APIs for CRUD operations using H2.
I think you have multiple fields that contains same name. That's the reason for repeated column.
Example:
private long deptId;
`#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "deptId", nullable = false)
public Department getDepartment() {
return department;
}`
There is already a column named depId (long type in ur field) and again you are trying to add Department with same column name ( #JoinColumn(name = "deptId", nullable = false) ) in your Joincolumn name. Try to change the JoinColumn name or add different column name to long datatype field.
There are 3 tables. There is the variable of "relatedCameraSet" need to order by "camera.name" using SQL, but the field of "camera.name" is not in table of "RelatedCamera", is in the outer joined table of "Camera". The following annotation of #OrderBy doesn't work.
#Entity
#Table(name = "MICRO_MAP")
public class MicroMap { //main table
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "ID")
private Long id;
#Column(name = "NAME", length = 32, nullable = false)
private String name;
#OneToMany(mappedBy="mapId",cascade=CascadeType.ALL, fetch=FetchType.EAGER)
#OrderBy("camera.name") //OrderBy the field of "name" in Camera table
private Set<RelatedCamera> relatedCameraSet;
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 Set<RelatedCamera> getRelatedCameraSet() {
return relatedCameraSet;
}
public void setRelatedCameraSet(Set<RelatedCamera> relatedCameraSet) {
this.relatedCameraSet = relatedCameraSet;
}
}
#Entity
#Table(name = "RELATED_CAMERA")
public class RelatedCamera {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "ID")
private Long id;
#Column(name = "MAP_ID")
private String mapId;
#ManyToOne(cascade=CascadeType.ALL, fetch=FetchType.EAGER)
#JoinColumn(name = "CAMERA_ID", referencedColumnName="id",nullable = true)
private Camera camera;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getMapId() {
return mapId;
}
public void setMapId(String mapId) {
this.mapId = mapId;
}
public Camera getCamera() {
return camera;
}
public void setCamera(Camera camera) {
this.camera = camera;
}
}
#Entity
#Table(name = "CAMERA")
public class Camera {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "ID")
private Long id;
#Column(name = "NAME")
private String 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;
}
}
How to write #OrderBy annotation in order to sort collection by camera name using SQL?
Thanks alot!
I researched your problem and found that from the API docs:
Hibernate JPA 2.1 API
The property or field name must correspond to that of a persistent property or field of the associated class or embedded class within it.
that's why it is not possible do it by just OrderBy, you can order only by camera_id column from MicroMap class.
What you want can be done by #Sort and implementing Comparable interface or by specifying a Comparator:
Annotation Type Sort
Now i realize it's impossible to do by #OrderBy, and i think it's not efficient to to do by implementing Comparable interface or specifying a Comparator, because it will take two steps to get job done, the step one is query from DB, the step two is sorting in memory. It's efficient to get sorted collection just by SQL.
In order to get high efficiency, i have to change the class of MicroMap as following:
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
#Entity
#Table(name = "MICRO_MAP")
public class MicroMap {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "ID")
private Long id;
#Column(name = "NAME", length = 32, nullable = false)
private String name;
// #OneToMany(mappedBy="mapId",cascade=CascadeType.ALL, fetch=FetchType.EAGER)
// #OrderBy("camera.name") //OrderBy the field of "name" in Camera table, But JPA doesn't support
// private Set<RelatedCamera> relatedCameraSet;
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;
}
}
and add a method in DAO or Service class.
public List<RelatedCamera> getRelatedCamera(Long mapId) {
Session session = sessionFactory.getCurrentSession();
List<RelatedCamera> list = session.createQuery(" from RelatedCamera where mapId="+mapId+" order by camera.name").list();
return list;
}
I have two entity class Category and Events.I need to join both the tables and fetch all records which matching the given condition
My sql query for this
SELECT * FROM category c inner join `events` e on e.category_i=c.category_id where c.parent_category_id=1;
How i can convert this sql query to hql and fetch the data ? I tried below but not getting the result ? Am very new to hibernate
Events entity class for hibernate mapping
import java.io.Serializable;
import java.util.Date;
import javax.persistence.*;
/**
* The persistent class for the user database table.
*
*/
#Entity
#Table(name = "events")
public class Events implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "event_id")
private int eventId;
#Column(name = "event_name")
private String eventName;
#Column(name = "event_description")
private String eventDescription;
#Column(name = "category_i")
private Integer categoryI;
public Integer getCategoryI() {
return categoryI;
}
public void setCategoryI(Integer categoryI) {
this.categoryI = categoryI;
}
#Column(name = "is_trending_event")
private Integer isTrendingEvent;
#Column(name = "image_url")
private String imageUrl;
private Integer status;
#Column(name = "created_date")
#Temporal(javax.persistence.TemporalType.DATE)
private Date createdDate;
#Column(name = "last_updated_date")
#Temporal(javax.persistence.TemporalType.DATE)
private Date lastUpdatedDate;
public Date getCreatedDate() {
return createdDate;
}
public void setCreatedDate(Date createdDate) {
this.createdDate = createdDate;
}
public Date getLastUpdatedDate() {
return lastUpdatedDate;
}
public void setLastUpdatedDate(Date lastUpdatedDate) {
this.lastUpdatedDate = lastUpdatedDate;
}
public int getEventId() {
return eventId;
}
public void setEventId(int eventId) {
this.eventId = eventId;
}
public String getEventName() {
return eventName;
}
public void setEventName(String eventName) {
this.eventName = eventName;
}
public String getEventDescription() {
return eventDescription;
}
public void setEventDescription(String eventDescription) {
this.eventDescription = eventDescription;
}
public Integer getIsTrendingEvent() {
return isTrendingEvent;
}
public void setIsTrendingEvent(Integer isTrendingEvent) {
this.isTrendingEvent = isTrendingEvent;
}
public String getImageUrl() {
return imageUrl;
}
public void setImageUrl(String imageUrl) {
this.imageUrl = imageUrl;
}
public Integer getStatus() {
return status;
}
public void setStatus(Integer status) {
this.status = status;
}
}
Category entity
import java.io.Serializable;
import java.util.Date;
import javax.persistence.*;
/**
* The persistent class for the user database table.
*
*/
#Entity
#Table(name = "category")
public class Category implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "category_id")
private int categoryId;
#Column(name = "category_name")
private String categoryName;
#Column(name = "parent_category_id")
private Integer parentCategoryId;
#Column(name = "created_date")
#Temporal(javax.persistence.TemporalType.DATE)
private Date createdDate;
#Column(name = "last_updated_date")
#Temporal(javax.persistence.TemporalType.DATE)
private Date lastUpdatedDate;
#ManyToOne
#JoinTable(name="events", joinColumns = #JoinColumn(name="category_i"))
private Events events;
public int getCategoryId() {
return categoryId;
}
public void setCategoryId(int categoryId) {
this.categoryId = categoryId;
}
public String getCategoryName() {
return categoryName;
}
public void setCategoryName(String categoryName) {
this.categoryName = categoryName;
}
public Integer getParentCategoryId() {
return parentCategoryId;
}
public void setParentCategoryId(Integer parentCategoryId) {
this.parentCategoryId = parentCategoryId;
}
public Date getCreatedDate() {
return createdDate;
}
public void setCreatedDate(Date createdDate) {
this.createdDate = createdDate;
}
public Date getLastUpdatedDate() {
return lastUpdatedDate;
}
public void setLastUpdatedDate(Date lastUpdatedDate) {
this.lastUpdatedDate = lastUpdatedDate;
}
}
Fetch category method
public List<Object[]> getCategoryList(int id) throws SQLException, ClassNotFoundException, IOException {
List<Object[]> groupList = null;
try {
Session session = sessionFactory.getCurrentSession();
Query query = session.createQuery("select e from Category e inner join e.events where e.parentCategoryId=1");
//query.setParameter("id", id);
groupList = query.list();
} catch (Exception e) {
}
return groupList;
}
You need to think in terms of Java objects when using ORM tools.
From your question I think the query that you're trying to write will look something like:
public List<Category> getCategoryList(int id) {
List<Category> groupList;
Session session = sessionFactory.getCurrentSession();
Query query = session.createQuery("select c from Category c join fetch c.events where c.parentCategory.categoryId = 1");
//query.setParameter("id", id);
groupList = query.list();
return groupList;
}
One of the benefits of using an ORM is that it works out the full join query for you.
For this to work you need to update your class model as follows:
import java.io.Serializable;
import java.util.Date;
import javax.persistence.*;
#Entity
#Table(name = "events")
public class Event implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "event_id")
private int eventId;
#Column(name = "event_name")
private String eventName;
#Column(name = "event_description")
private String eventDescription;
#ManyToOne
#JoinColumn(name = "category_i")
private Category category;
#Column(name = "is_trending_event")
private Integer isTrendingEvent;
#Column(name = "image_url")
private String imageUrl;
private Integer status;
#Column(name = "created_date")
#Temporal(javax.persistence.TemporalType.DATE)
private Date createdDate;
#Column(name = "last_updated_date")
#Temporal(javax.persistence.TemporalType.DATE)
private Date lastUpdatedDate;
...
}
and
import java.io.Serializable;
import java.util.Date;
import javax.persistence.*;
#Entity
#Table(name = "category")
public class Category implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "category_id")
private int categoryId;
#Column(name = "category_name")
private String categoryName;
#ManyToOne
#JoinColumn(name="parent_category_id")
private Category parentCategory;
#Column(name = "created_date")
#Temporal(javax.persistence.TemporalType.DATE)
private Date createdDate;
#Column(name = "last_updated_date")
#Temporal(javax.persistence.TemporalType.DATE)
private Date lastUpdatedDate;
#OneToMany(mappedBy="category")
private List<Event> events;
...
}
Hibernate is about mapping objects and the relations, however you are mapping simple id fields.
In your Events class you have the followingL
#Entity
#Table(name = "events")
public class Events implements Serializable {
#Column(name = "category_i")
private Integer categoryI;
}
However it should be a Category instead of an Integer.
#Entity
#Table(name = "events")
public class Events implements Serializable {
#ManyToOne
#Column(name = "category_i")
private Category category;
}
Then in your Category you should add the mappedBy field to the #ManyToOne on the events field and remove the #JoinColumn.
#Entity
#Table(name = "category")
public class Category implements Serializable {
#OneToMany(mappedBy="category")
private Events events;
}
The same applies to the parentCategoryId of the Category class.
Now that you have your mapping corrected you should be able to write the query as you wanted to.
This query should do the job:
from Category as c
inner join c.events as e
where c.parentCategoryId = 1
Plus you seem to have a typo (missing "d" at the end) here:
#JoinColumn(name="category_i"))
Ty this below code
public List<Object[]> getCategoryList(int id) throws SQLException, ClassNotFoundException, IOException {
Session session = sessionFactory.getCurrentSession();
return session.createCriteria(Catagory.class)
.setFetchMode("events", FetchMode.JOIN)
.add(Restrictions.eq("parentCatagoryId", 1))
.list();
}
Hope this stuff works.
Here's what I had to write to get UUID working as a primary key, with full UUID types (on all ends) in hibernate. Since this relies on some Hibernate specific code, what would I have to do to convert this code to work on eclipselink?
package com.lm.model;
import org.hibernate.annotations.GenericGenerator;
import org.hibernate.annotations.Type;
import javax.persistence.*;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import java.util.UUID;
#Entity
#Table(name = "tasks")
public class Task {
#Id
#NotNull
#Type(type = "pg-uuid")
#GeneratedValue(generator = "myUUIDGenerator")
#GenericGenerator(name = "myUUIDGenerator", strategy = "uuid2")
#Column(name = "task_id", columnDefinition = "uuid")
private UUID id;
#NotNull
#Size(min = 1, max = 100)
private String description;
public String getDescription() {
return description;
}
public void setDescription(final String description) {
this.description = description;
}
public UUID getId() {
return id;
}
public void setId(final UUID id) {
this.id = id;
}
}
Here is another case of this ERROR:
21:22:15,881 ERROR [SessionFactoryImpl] Error in named query: ch.software.gvs.TroubleNotification_DeviceType.byType org.hibernate.QueryException:
could not resolve property: type of: ch.ildsoftware.gvs.TroubleNotification_DeviceType
[select d.id from ch.ildsoftware.gvs.TroubleNotification_DeviceType d where d.type = :type]
I have following setting:
queries.xml:
<named-query name="ch.ildsoftware.gvs.TroubleNotification_DeviceType.byType">
<query>
select t.id from TroubleNotification_DeviceType t where t.type = :type
</query>
</named-query>
TroubleNotification_DeviceType.java
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;
#Entity
#Table(name = "tblgwTroubleNotification_ADSTyp")
public class TroubleNotification_DeviceType implements Serializable {
private static final long serialVersionUID = 1L;
private TroubleNotification id;
private DeviceType type;
private String createdBy;
private String createdDate;
public TroubleNotification_DeviceType()
{}
public TroubleNotification_DeviceType(TroubleNotification id, DeviceType type) {
this.id = id;
this.type = type;
}
#Id
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "IDgwTroubleNotification", nullable = false)
public TroubleNotification getId() {
return id;
}
public void setId(TroubleNotification id) {
this.id = id;
}
#Id
#Column(name = "ADSTypID", nullable = false)
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "GeraeteTypID", nullable = false)
public DeviceType getType() {
return type;
}
public void setType(DeviceType type) {
this.type = type;
}
#Column(name = "Created", nullable = false)
public String getCreatedBy() {
return createdBy;
}
public void setCreatedBy(String createdBy) {
this.createdBy = createdBy;
}
#Column(name = "CreatedDate", nullable = false)
public String getCreatedDate() {
return createdDate;
}
public void setCreatedDate(String createdDate) {
this.createdDate = createdDate;
}
}
I suspect there might be something wrong with the #Column and #JoinColumn annotation. It's just that the column-name I join with, is from a view which aliases the column name.
But maybe something else is wrong. I'm rather new to this.
snippet out of DeviceType:
private static final long serialVersionUID = 1L;
private Integer id;
private String name;
....
#Id
#Column(name = "GeraeteTypID", nullable = false)
public Integer getId()
{
return this.id;
}
In other classes the reference would be like this, and work well (yet the column name is identical):
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "GeraeteTypID", nullable = false)
public DeviceType getType()
{
return this.type;
}
snippet out of an EJB:
#Override
#SuppressWarnings("unchecked")
public List<TroubleNotification> getTroubleNotificationByDeviceType(DeviceType aType)
{
// first get all IDgwTroubleNotification for ADSTypID
Query idSet = gvsData.createNamedQuery(
TroubleNotification_DeviceType.class.getName() + ".byType");
idSet.setParameter("type", aType);
List<TroubleNotification> idSetResult = idSet.getResultList();
final List<TroubleNotification> troubleNotificationResult = new ArrayList<TroubleNotification>();
for (int i = 0; i < idSetResult.size(); i++) {
// get all Notification for IDgwTroubleNotification
Query notificationById = gvsData.createNamedQuery(
TroubleNotification.class.getName() + ".byId");
notificationById.setParameter("id", idSetResult.get(i));
troubleNotificationResult.add((TroubleNotification) notificationById.getResultList());
}
return troubleNotificationResult;
}
Thank you for your help!
I discovered that my DB mapping was not at all proper. I have an n:m relation, which doesn't seem like an easy one with hibernate. But this was very helpful:
Hibernate Many-To-Many Revisited
But that was still not solving the problem. And I discovered that I have composite primary keys, that the primary keys of two tables are mapped in the n:m table. Another not so easy setting. So I followed this thread: Mapping ManyToMany with composite Primary key and Annotation:
The configuration from the second link, together with an SQL statement according to the second strategy in the first link works.