I want to query data from two tables,
location field in Translation is a foreign key from id field of Location
#Entity
#Table(name = "Translation")
#Data
public class Translation {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
#NotNull private String language;
#NotNull private String name;
#NotNull private String description;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "location", nullable = false, insertable = false, updatable = false)
#Fetch(FetchMode.JOIN)
private Location location;
}
#Entity
#Table(name = "Location")
#Data
public class Location {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
#NotNull private String code;
#NotNull private String type;
private Double longitude;
private Double latitude;
#Column(name = "parent_id")
private Integer parentId;
#OneToMany(targetEntity = Translation.class, mappedBy="id", fetch = FetchType.EAGER)
private Set<Translation> translations;
}
————————————————————————————————————————
But when I use a query
#Query(
"SELECT new com.afkl.travel.exercise.model.RetrieveLocationResponse("
+ "loc.code, tran.name, loc.type, loc.latitude, loc.longitude, tran.description, loc.parentId)"
+ "FROM Location loc LEFT JOIN loc.translation tran")
List<RetrieveLocationResponse> fetchLeftJoin();
All the fields related to Translation is null, having no idea what happened
UPDATE
The following ones work for me.
#OneToMany(mappedBy = "location", cascade = CascadeType.ALL)
#JsonIgnore
private Set<Translation> translations;
#ManyToOne
#JoinColumn(name = "location")
private Location location;
try
#OneToMany(mappedBy = "location", cascade = CascadeType.ALL)
#JsonIgnore
private Set<Translation> translations;
#ManyToOne
#JoinColumn(name = "location")
private Location location;
Related
I made 2 one-to-one relationships with 2 foreign keys, but I can't make a constraint or how could I make the 2 unique keys be a unique key in the new table?
#Table(name = "cart")
public class Cart {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id", nullable = false)
private Long id;
private int quantity;
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "product_id")
private Product products;
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "user_id")
private User users;
}
#Entity
#Table(name = "Products")
public class Product {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String name;
private int quantity;
private Double price;
private String image;
It spells my 2 keys correctly, for example
user_id = 2 , product_id =2 would be ok
but if I enter another user_id=2, product_id=2 should not work, but for me it is entered in the database
You can use #PrimaryKeyJoinColumn in the #OneToOne relation:
#OneToOne(cascade = CascadeType.ALL)
#PrimaryKeyJoinColumn(name = "product_id", referencedColumnName = "id")
private Product products;
Im making an bungalow reservation system but i cant get a list with an many to many relationship i keep getting an infinite list with stackoverflow error.
This worked find but happens when i added the many to many relationship.
Attraction Entity this contains a many to many relationship with
the visit entity
#Entity
#Table(name = "attraction")
public class Attraction {
#Id
#Column(name = "id")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
#Column(name = "name")
private String name;
#Column(name = "historical")
private Boolean historical;
#Column(name = "religious")
private Boolean religious;
#Column(name = "beaches")
private Boolean beaches;
#Column(name = "animal_sanc")
private Boolean animalSanc;
#Column(name = "hiking")
private Boolean hiking;
#Column(name = "forest")
private Boolean forest;
#Column(name = "parks")
private Boolean parks;
#Column(name = "lakes")
private Boolean lakes;
#ManyToOne
#JoinColumn(name = "bungalow_id")
private Bungalow bungalow;
#ManyToMany(cascade = {CascadeType.MERGE,CascadeType.REFRESH})
#JoinTable(
name = "visit_has_attraction",
joinColumns = #JoinColumn(name = "attraction_id"),
inverseJoinColumns = #JoinColumn(name = "visit_id")
)
private List<Visit> visitList;
//Constructer, Getters and Setters
}
Visit entity
This is the other end of the many to many relationship
#Entity
#Table(name = "visit")
public class Visit {
#Id
#Column(name = "id")
private int id;
#Column(name = "date")
private Date date;
#ManyToOne
#JoinColumn(name = "user_id")
private User user;
#ManyToMany(cascade = {CascadeType.MERGE,CascadeType.REFRESH})
#JoinTable(
name = "visit_has_attraction",
joinColumns = #JoinColumn(name = "visit_id"),
inverseJoinColumns = #JoinColumn(name = "attraction_id")
)
List<Attraction> attractions;
//Constructer, Getters and Setters
}
JPA Repository
public List<Attraction> findAttractionsByVisitList(Visit visit);
ER of the app
1
I added #JsonIgnore to one of the sides in many to many relationships and added #JsonBackReference to ManyToOne side and #JsonManagedReference to OneToMany side of all the one to many relationships.
#Entity
#Table(name = "attraction")
public class Attraction {
#Id
#Column(name = "id")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
#Column(name = "name")
private String name;
#Column(name = "historical")
private Boolean historical;
#Column(name = "religious")
private Boolean religious;
#Column(name = "beaches")
private Boolean beaches;
#Column(name = "animal_sanc")
private Boolean animalSanc;
#Column(name = "hiking")
private Boolean hiking;
#Column(name = "forest")
private Boolean forest;
#Column(name = "parks")
private Boolean parks;
#Column(name = "lakes")
private Boolean lakes;
#ManyToOne
#JoinColumn(name = "bungalow_id")
#JsonBackReference
private Bungalow bungalow;
#ManyToMany(cascade = {CascadeType.MERGE,CascadeType.REFRESH})
#JoinTable(
name = "visit_has_attraction",
joinColumns = #JoinColumn(name = "attraction_id"),
inverseJoinColumns = #JoinColumn(name = "visit_id")
)
#JsonIgnore
private List<Visit> visitList;
//Constructer, Getters and Setters
}
Visit entity
This is the other end of the many to many relationship
#Entity
#Table(name = "visit")
public class Visit {
#Id
#Column(name = "id")
private int id;
#Column(name = "date")
private Date date;
#ManyToOne
#JoinColumn(name = "user_id")
#JsonBackReference
private User user;
#ManyToMany(cascade = {CascadeType.MERGE,CascadeType.REFRESH})
#JoinTable(
name = "visit_has_attraction",
joinColumns = #JoinColumn(name = "visit_id"),
inverseJoinColumns = #JoinColumn(name = "attraction_id")
)
List<Attraction> attractions;
//Constructer, Getters and Setters
}
I am getting StackOverflow recursion error when I run query in Postman or Browser .
When i run says:
.w.s.m.s.DefaultHandlerExceptionResolver : Could not write JSON: Infinite recursion (StackOverflowError); nested exception is com.fasterxml.jackson.databind.JsonMappingException: Infinite recursion (StackOverflowError)
Here is the model classes :
#Entity
public class Product {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#NotNull
private String title;
#NotNull
private String description;
#NotNull
private double price;
#OneToOne(fetch = FetchType.LAZY, optional = false)
#JoinColumn(name = "category_id", nullable = false)
private Category category;
private boolean isSealed;
#OneToOne(fetch = FetchType.LAZY, optional = false)
#JoinColumn(name = "currency_id", nullable = false)
private Currency currency;
#OneToOne(fetch = FetchType.LAZY, optional = false)
#JoinColumn(name = "user_id", nullable = false)
private User user;
#Nullable
#OneToMany(mappedBy = "product",
cascade = CascadeType.ALL, orphanRemoval = true)
private List<Images> images;
private Date createdDate = new Date();
#OneToOne(fetch = FetchType.LAZY,
cascade = CascadeType.ALL,
mappedBy = "product")
private View view;
#OneToOne(fetch = FetchType.LAZY,cascade=CascadeType.ALL)
#JoinColumn(name="type_id")
private Type type;
private Long viewCount; }
#Entity public class Images{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String imagePath;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "product_id")
private Product product; }
#Entity public class User implements UserDetails, Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#NotEmpty
private String fullName;
#NotEmpty
#Email
#Column(unique = true)
private String email;
#NotNull
#Column(unique = true)
private int phoneNumber;
#NotEmpty
#Size(min = 5)
private String password;
private Date createAt = new Date();
#Nullable
private String picPath;
#Nullable
private String token;
#ManyToMany
#JoinTable(name = "user_roles", joinColumns = {#JoinColumn(
name = "user_id")},
inverseJoinColumns = {#JoinColumn(name = "role_id")})
private List<Role> roles;
#OneToOne(fetch = FetchType.LAZY,
cascade = CascadeType.ALL,
mappedBy = "user")
private Product product;
#OneToOne(fetch = FetchType.LAZY,
cascade = CascadeType.ALL,
mappedBy = "user")
private View view; }
#Entity
public class Currency{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String code;
private String currency;
private String region_country;
#OneToOne(mappedBy = "currency", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
private Product product; }
#Entity
public class Category {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
private String imagePath;
#OneToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY,
mappedBy = "category")
private Product product;
#OneToMany(mappedBy = "category", fetch = FetchType.LAZY,
cascade = CascadeType.ALL)
private Set<Brand> brands; }
#Entity public class Brand {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
#ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
#JoinColumn(name = "category_id", nullable = false)
private Category category; }
#Entity public class View {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#OneToOne(fetch = FetchType.LAZY, optional = false)
#JoinColumn(name = "user_id", nullable = false)
private User user;
#OneToOne(fetch = FetchType.LAZY, optional = false)
#JoinColumn(name = "product_id", nullable = false)
private Product product; }
#Entity public class Type {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#NotNull
private String name;
#OneToOne(fetch = FetchType.LAZY,
cascade = CascadeType.ALL,
mappedBy = "type")
private Product product; }
#Id
private String role;
#ManyToMany(mappedBy = "roles")
private List<User> users;
}
More than one of your entities have each other in themselves.
For example, Product has an object of User, and User has an object of Product.
To solve this, you have to write
#JsonBackReference(value = "user-product")
private User user;
in the Product class,
and
#JsonManagedReference(value = "user-product")
private Product product;
In the user class.
Do it in every field and for every class that call each other.
Also, Check this out
JPA: Having lists on both ends without infinite loop
You have cycles in your data model. For example, Product holds Images and Images point back to Products.
This works in an object oriented world, because only pointer references are stored in those fields.
When serialized, however, the actual object is written out as json text. Your Product prints the Images object which in turn prints the Product object which again prints the Image object and so on.
You need to decide how you want to represent your json, map your database model into simple plain old java object and use this for serializations. These POJOs are often called View Model or Transport Objects.
I have a problem with the relationship oneToMany. I created tables in SQLite DB, this is my tables:
My CategoryModel:
#Entity
#Table(name = "Category")
#JsonIgnoreProperties({ "hibernateLazyInitializer", "handler" })
public class CategoryModel {
#Id
#Column(name = "id")
#GeneratedValue(strategy = GenerationType.AUTO)
private int id;
private String category_name;
private String category_description;
private String image_path;
#JsonIgnore
#OneToMany( mappedBy = "category")
private Set<ProductModel> category;
My ProducCategory:
#Entity
#Table(name = "Product_Category")
#JsonIgnoreProperties({ "hibernateLazyInitializer", "handler" })
public class ProductModel {
#Id
#Column(name = "id")
#GeneratedValue(strategy = GenerationType.AUTO)
private Long product_id;
private Long category_id;
private String name;
private String description;
private int numberOfProduct;
private String image;
private int price;
#ManyToOne
#JoinColumn(name = "country_id", nullable = false)
private CategoryModel category;
I can get data from the Category table well but when I call data from the Product_Category table I have the error:
SQL error or missing database (no such column: productmod0_.country_id)
country_id does not exist anywhere in your tables.
What you want is : #JoinColumn(name = "category_id", nullable = false)
I have two JPA entities: User and Message.
Each Message has one sender and one receiver of type User. And on the other side each User has two sets of type Message: inbox and outbox.
Message:
#Entity
#Table(name = "messages")
public class Message {
#Id
#GeneratedValue(strategy = GenerationType.AUTO, generator = "seq")
#SequenceGenerator(name = "seq", sequenceName = "MESSAGES_SEQ")
#Column(name = "ID", insertable = false, updatable = false)
private int id;
#ManyToOne
#JoinColumn(name = "SENDER")
private User sender;
#ManyToOne
#JoinColumn(name = "RECEIVER")
private User receiver;
private String subject, content;
private Date sdate;
//getters and setters
}
All the properties which not being mapped with an annotation has he same name as the columns in database and are automatically mapped by JPA.
User:
#Entity
#Table(name = "users")
public class User {
#Column(name = "USERNAME")
private String username;
#Column(name = "PASSWORD")
private String pass;
#Column(name = "EMAIL")
private String email;
#Id
#GeneratedValue(strategy = GenerationType.AUTO, generator = "seq")
#SequenceGenerator(name = "seq", sequenceName = "USERS_SEQ")
#Column(name = "ID", insertable = false, updatable = false)
private int id;
#OneToMany(mappedBy = "uploader")
private Set<Book> books;
#OneToMany(mappedBy = "receiver")
private Set<Message> inbox;
#OneToMany(mappedBy = "sender")
private Set<Message> outbox;
//getters and setters
}
The problem is, when I select an User from Oracle database, then the inbox property is empty. How is this caused and how can I solve it?