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
Related
I have created JPA entities class. But using basic query taking humongous amount of time for basic sql query having 100 records in database.
I have 4 tables. (Group/GroupA/GroupB/GroupC) having below structure.
#Table(name = "group")
public class Group implements Serializable {
#Id
#Column(name = "id")
private String id;
#Column(name = "publish_date")
private LocalDate publishDate;
#OneToOne(mappedBy = "group", cascade = CascadeType.ALL)
private GroupA groupA;
#OneToOne(mappedBy = "group", cascade = CascadeType.ALL)
private GroupB groupB;
#OneToOne(mappedBy = "group", cascade = CascadeType.ALL)
private GroupC groupC;
}
#Table(name = "groupA")
public class GroupA {
#Id
#Column(name = "group_id")
private Long groupID;
#Column(name = "name")
private String name;
#OneToOne
#JoinColumn(name = "id")
#JsonIgnore
private Group Group;
}
#Table(name = "groupB")
public class GroupB {
#Id
#Column(name = "group_id")
private Long groupID;
#Column(name = "name")
private String name;
#OneToOne
#JoinColumn(name = "id")
#JsonIgnore
private Group Group;
}
#Table(name = "groupC")
public class GroupC {
#Id
#Column(name = "group_id")
private Long groupID;
#Column(name = "name")
private String name;
#OneToOne
#JoinColumn(name = "id")
#JsonIgnore
private Group Group;
}
Repository class:
#Repository
public interface GroupRepository extends JpaRepository<Group, Long> {
#Query("select r from Group r WHERE r.publishDate = ?1")
List<Group> findAllGroupForDate(LocalDate businessDate);
}
The above basic query is taking 1 minute 30 seconds for around 100 rows in Main Group table.
Please help if I am making anything wrong in entity class.
THanks.
Try to use the Lazy loading concept.
#OneToOne(mappedBy = "group", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
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 2 tables called Product and Category with many-to-many relationship. And Product has a one-to-many relationship with Images table. I created a table Product_Category to link 2 table Product and Category together. My problem is when 1 product belongs to 1 category, it's just fine with 4 images of that product. But if 1 product belongs to 2 categories, i get 8 images instead of 4
This is image of problem
As you can see is's supposed to be _1 _2 _3 _4 instead _1 _1 _2 _2 ...
This is my entities class
ProductEntity
#Entity
#Table(name = "product")
public class ProductEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
#Column(name = "name")
private String name;
#Column(name = "description")
private String description;
#Column(name = "price")
private double price;
#Column(name = "material")
private String material;
#ManyToOne
#JoinColumn(name="careId")
private ProductCareEntity productCare;
#OneToMany(mappedBy = "product", fetch = FetchType.EAGER)
private List<ImageEntity> images;
#OneToMany(mappedBy = "product", fetch = FetchType.EAGER)
private List<ProductCategoryEntity> productCategoryEntities;
#OneToMany(mappedBy = "product", fetch = FetchType.EAGER)
private List<OrderDetailEntity> orderDetailEntityList;
#OneToMany(mappedBy = "product", fetch = FetchType.EAGER,cascade=CascadeType.ALL)
private List<ProductSizeQuantityEntity> productSizeQuantities;
CategoryEntity
#Entity
#Table(name = "category")
public class CategoryEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
#Column(name = "name")
private String name;
#OneToMany(mappedBy = "category", fetch = FetchType.EAGER)
private List<ProductCategoryEntity> productCategories;
ProductCategoryEntity
#Entity
#Table(name = "product_category")
public class ProductCategoryEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
#ManyToOne
#JoinColumn(name = "categoryId")
private CategoryEntity category;
#ManyToOne
#JoinColumn(name = "productId")
private ProductEntity product;
How can i solve this problem?
I don't think you need ProductCategoryEntity at all. All you need to do is to make a List of Category type in product and List of Product type in Category. like this:
#Entity
#Table(name = "product")
public class ProductEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
#Column(name = "name")
private String name;
#Column(name = "description")
private String description;
#Column(name = "price")
private double price;
#Column(name = "material")
private String material;
#ManyToOne
#JoinColumn(name="careId")
private ProductCareEntity productCare;
#OneToMany(mappedBy = "product", fetch = FetchType.EAGER)
private List<ImageEntity> images;
#ManyToMany(cascade = { CascadeType.ALL })
#JoinTable(name = "ProductCategory",
joinColumns = { #JoinColumn(name = "category_id") },
inverseJoinColumns = { #JoinColumn(name = "product_id"))
private List<Category> categories;
#OneToMany(mappedBy = "product", fetch = FetchType.EAGER)
private List<OrderDetailEntity> orderDetailEntityList;
#OneToMany(mappedBy = "product", fetch =
FetchType.EAGER,cascade=CascadeType.ALL)
private List<ProductSizeQuantityEntity> productSizeQuantities;
and
#Entity
#Table(name = "category")
public class CategoryEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
#Column(name = "name")
private String name;
#ManyToMany(mappedBy = "projects")
#JoinTable(name = "ProductCategory")
private List<Product> products;
I have 4 entities: Play, Actor, Play-representation and Category.
Each play belongs to a category and play-representation associates a play with a theater and a number of actors at a given time.
Here are the entities:
#Entity
#Table(name = "category")
public class Category {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
#Column(name = "name")
private String name;
#OneToMany(mappedBy="category")
private List<Play> playList = new ArrayList<Play>();
#Entity
#Table(name = "actor")
public class Actor {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private long id;
#Column(name = "first_name")
private String firstName;
#Column(name = "last_name")
private String lastName;
#Column(name = "description")
private String description;
#Column(name = "profile_picture")
private String profilePicturePath;
#ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
#JoinTable(name = "play_representation_category",
joinColumns = {#JoinColumn(name = "actor_id")},
inverseJoinColumns = {#JoinColumn(name = "play_representation_id")})
private Set<PlayRepresentation> playRepresentations = new HashSet<>(0);
#Entity
#Table(name = "play")
public class Play {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
#NotNull
#Column(name = "name")
private String name;
#NotNull
#Column(name = "description")
private String description;
#Column(name = "image_paths")
private String imagePaths;
#NotNull
#ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
private Category category;
#Entity
#Table(name = "play_representation")
public class PlayRepresentation {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "play_id")
private Play play;
#OneToOne
#JoinColumn(name = "theater_id")
private Theater theater;
#Column(name = "date")
private Timestamp airingDate;
#ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
#JoinTable(name = "play_representation_category",
joinColumns = {#JoinColumn(name = "play_representation_id", nullable=false)},
inverseJoinColumns = {#JoinColumn(name = "actor_id", nullable=false)})
private Set<Actor> actors = new HashSet<>(0);
The issue I'm having is that hibernate is trying to find a relationship between play_representation and category! I've been trying to persist the relationship for the plays but it seems I got that wrong and can't figure out the best way to do it...It's a postgresql db by the way.
I am still learning, so if you have any other tips regarding the code I've shared, please let me know!
Edit: error is:
org.postgresql.util.PSQLException: ERROR: relation "play_representation_category" does not exist
Position: 281
I didn't need a mappedBy, it was actually a typo - I wrote play_representation_category instead of play_representation_actors. Pretty stupid, huh? At least I finally found it :)
I use hibernate and spring-data. There are two tables with many-to-many relationship.
#Entity
#Table(name = "FirstEntity")
public class FirstEntity {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "first_entity_id")
private Long id;
#Column(name = "first_entiry_name")
private String name;
/* getters and setters are below*/
}
#Entity
#Table(name = "SecondEntity")
public class SecondEntity {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "second_entity_id")
private Long id;
#Column(name = "second_entiry_name")
private String name;
#Column(name = "second_entiry_desc")
private String description;
/* getters and setters are below*/
}
And entity for cross-reference table.
#Entity
#Table(name = "FirstSecondEntity")
public class FirstSecondEntity {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "first_second_entity_id")
private Long id;
#Column(name = "first_entity_id")
private Long firstEntityId;
#Column(name = "second_entity_id")
private Long secondEntityId;
/* getters and setters are below*/
}
I need SELECT like this
SELECT FirstEntity.name, SecondEntity.name, SecondEntity.description FROM SecondEntity INNER JOIN FirstSecondEntity ON SecondEntity.id = FirstSecondEntity.secondEntityId INNER JOIN User ON FirstEntity.id = FirstSecondEntity.firstEntityId
i.e. I need all records from cross-reference table where instead of ids there is actual info from entities.
Inserting this query into #Query annotation in my CrudRepository-extended class doesn't work because of
ERROR [main][org.hibernate.hql.internal.ast.ErrorCounter] Path expected for join!
So I need your help.
Your join table is all screwed up. In this case, you actually don't even need the join table as a hibernate mapping:
In Second Entity add the following list:
#ManyToMany(fetch = FetchType.LAZY)
#JoinTable(name = "FirstSecondEntity",
joinColumns = {
#JoinColumn(name = "first_entity_id",
nullable = false,
updatable = false) },
inverseJoinColumns = {
#JoinColumn(name = "second_entity_id",
nullable = false,
updatable = false) },
)
private List<FirstEntity> firstEntities;
In FirstEntity add the following list:
#ManyToMany(fetch = FetchType.LAZY,
mappedBy = "firstEntities")
private List<SecondEntity> secondEntities;