I have such a simple scheme
and the following entities:
#Entity
public class Ticket {
#Id
#GeneratedValue
private Integer id;
#ManyToOne
private Event event;
#OneToOne
private User user;
#Embedded
private Seat seat;
private TicketState state;
private Float price;
// getters, setters, etc.
#Entity
public class Event {
#Id
#GeneratedValue
private Integer id;
#OneToOne
private Movie movie;
#Embedded
private Auditorium auditorium;
private LocalDateTime startDateTime;
#OneToMany
private Set<Ticket> tickets = new HashSet<>();
// getters, setters, etc.
#Entity
public class User {
#Id
#GeneratedValue
private Integer id;
#Enumerated(EnumType.STRING)
private UserRole role;
private String name;
private String email;
private Instant birthday;
#OneToMany
private List<Ticket> tickets = new ArrayList<>();
private boolean lucky;
// getters, setters, etc.
#Embeddable
public class Auditorium {
private Integer id;
private String name;
private Integer seatsNumber;
#ElementCollection
private List<Integer> vipSeats;
// getters, setters, etc.
Also these entities was added to hibernate.cfg.xml.
Than I run app I have the following exception:
Caused by: org.hibernate.MappingException: Repeated column in mapping for entity: com.epam.spring.core.domain.Event column: id (should be mapped with insert="false" update="false")
At first glance I don't see any duplications in Event, as mentioned in exception. What should I fix in entities mapping description to resolve the problem according my scheme? Thank you!
Both Event and Auditorium map to column named id.
Specify a different column name in Auditorium or use #AttributeOverride in Event to override the default name.
When you map an entity with annotations, you do not need to repeat yourself on hibernate.cfg.xml. Try to delete it e run your code again.
Updating my answer based on Dragan Bozanovic's, Auditorium should NOT have an #Id annotated field (but we can't see that from your code, if it has).
Related
I am currently working on a project with following data structure:
public class PinaColadaId implements Serializable {
private UUID id;
#Temporal(TemporalType.TIMESTAMP)
private Date time;
// Constructor + Getters and Setters
}
#Entity
#Table(name = "pina_coladas")
#IdClass(PinaColadaId.class)
public class PinaColadaEntity {
#Column(columnDefinition = "char(255)")
#Type(type="org.hibernate.type.UUIDCharType")
private #Id UUID id;
private #Id #Temporal(TemporalType.TIMESTAMP) Date time;
#OneToOne(mappedBy = "entityID", cascade=CascadeType.ALL)
private PineappleWrapper pineapple;
#OneToMany(mappedBy = "entityID", cascade=CascadeType.ALL)
private List<CoconutWrapper> coconuts;
// Constructor + Getters and Setters
}
#Entity
public class PineappleWrapper {
private #Id #GeneratedValue long id;
private String manufacturer;
private String origin;
#OneToOne
private PinaColadaEntity entityID;
// Constructor + Getters and Setters
}
#Entity
public class CoconutWrapper {
private #Id #GeneratedValue long id;
private int shipmentNumber;
private int juice;
#ManyToOne
private PinaColadaEntity entityID;
// Constructor + Getters and Setters
}
The issue is that Spring Boot together with Hibernate and JPA correctly generate all the tables in my database, however when I attempt to store PineappleWrapper or CoconutWrapper, it stores all the values of PineappleWrapper and/or CoconutWrapper except for the id and time of the parent. The columns are generated yet they store the value "null".
Any and all help is much appreciated, -AwesomeDude091
Edit: I am aware of the JoinColumn annotation and it proposed implementation in my Wrapper classes, but I do not know how to use them with my two ID variables (id and time)
I'm trying to map those three entities to each other without adding any additional fields to any of them. They should only contain the fields that already exist. I'm also trying to only get columns in the tables that represent the currently existing entity fields- and no additional columns.
#Entity
public class Order {
#Id
private Integer orderId;
private String title;
private Customer customer;
private List<Comment> comments;
}
#Entity
public class Customer {
#Id
private Integer customerId;
private String name;
}
#Entity
public class Comment {
#Id
private Integer commentId;
private Integer orderId;
private String details;
}
My understanding is that I can't simply use #OneToOne, #OneToMany and #ManyToOne mappings, because neither Customer nor Comment has a reference to Order . I'm trying to somehow reference the ids of Customer and Comment directly from Order.
I've tried using #MapsId and #JoinColumn but either I don't know how to properly use them, or they don't do what I think they do.
Is this task at all possible? If so, how to map them to each other?
For the reference to Comment you must use #JoinColum
The Customer reference assumes that there is a customer_id on the order table.
#Entity
public class Order {
#Id
private Integer orderId;
private String title;
#ManyToOne
#JoinColumn(name = "customer_id")
private Customer customer;
#OneToMany
#JoinColumn(name = "comment_id")
private List<Comment> comments;
}
I have two entity classes, named Product and ComboProduct. Product contains all the information about a particular product and has a Primary Key productId. ComboProduct holds a list with a #OneToMany relationship to the Product and has a primary key named comboProductId. When I create multiple Comboproduct instances with the same set of products, I get the following DataIntegrityViolationException:
public class Product {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long productId;
#OneToOne
private MasterProduct masterProduct;
#NotBlank
private String productName;
private String productDescription;
private Double productSellingPrice; // mrp
private Double productOfferPrice; // price at which the user sells
private Double productPurchasePrice;
private float totalTaxPercentage;
private float productMargin;
#OneToOne
private MerchantStore store;
#ManyToOne
private ComboProduct comboProduct; #Entity
public class ComboProduct {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long comboProductId;
private String comboProductKey;
#OneToMany
private List<Product> products;
#NotBlank
private String comboName;
private String comboDescription;
org.springframework.dao.DataIntegrityViolationException:
could not execute statement; SQL [n/a];
constraint [UK_nm4dyaqp2f780nx73vq9abbw3];
nested exception is org.hibernate.exception.ConstraintViolationException:
could not execute statement\n\t
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.convertHibernateAccessException(HibernateJpaDialect.java:298)\n\t
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:255)\n\t
at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:538)\n\t
at org.springframework.transaction.support.
How can I resolve this?
as you have modeled a One-to-Many relationship, you defined that one combo is associated to multiple products. But products can only be assigned to one combo.
If you want products to be able to belong to multiple combos, you would need to model a Many-to-Many relationship. That would of course also imply to have a respective mapping table on the database.
Relationships between the 2 entity classes were not established properly.
`
#Entity
public class Product {
#Id
#GeneratedValue (strategy = GenerationType.IDENTITY)
private Long productId;
#ManyToOne
private ComboProduct comboProduct; }
#Entity
public class ComboProduct {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long comboProductId;
#OneToMany
private List<Product> products;
} `
The problem is you need to tell Hibernate that the OneToMany mapping will use a foreign key on another table, otherwise, it will assume that the entity in the list must have a unique Id.
To do so, you must add #JoinColumn on the attribute owning the mapping (class ComboProduct attribute products).
Try the following:
#Entity
public class ComboProduct {
...
#OneToMany(mappedBy = "comboProduct")
private List<Product> products;
#Entity
public class Product {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long productId;
private String productDescription;
private Double productSellingPrice;
private Double productOfferPrice;
#ManyToOne
#JoinColumn
private ComboProduct comboProduct;
}
OK, so I've designed a basic CRUD an an exercise. It has 2 tables Jobs and Employees. I'm trying to create a many to one relationship, but when I click the link to go to the Employee Entry page it throws an error that kicks off with the #ManyToOne referencing an Unknown Entity.
Here is what I've got in my Employees.java
String jobName;
#ManyToOne(fetch=FetchType.EAGER)
#Fetch(value = FetchMode.JOIN)
#JoinColumn(name = "Job_Name")
#Column (name='jobName')
public String getJobName() {
return jobName;
}
public void setJobName(String jobName) {
this.jobName = jobName;
}
Any idea what i"m doing wrong and how to resolve this?
As per your comment,i think you can define relationship between these two entities like below.
#Entity
#Table(name="employee")
class Employee{
#Id
#GeneratedValue
private Integer id;
#ManyToOne
#JoinColumn(name = "job_name")
private Job job;
// other column and getter and setter
}
#Entity
#Table(name="job")
class Job{
#Id
#GeneratedValue
private Integer id;
#Column(name="job_name")
private String jobName;
//provide other column and getter setter
}
Database
*user_account*
id (PK)
email
password
*user_detail*
id(PK)(FK)
name
city
Entities
#Table(name="user_detail")
public class UserDetail implementsSerializable{
#Id private Integer id;
...
#OneToOne
#JoinColumn(name="id")
private UserAccount userAccount;
}
#Table(name="user_account")
public class UserAccount implementsSerializable{
#Id private Integer id;
#OneToOne(mappedBy="userAccount")
private UserDetail userDetails;
}
Error
Exception Description: Multiple writable mappings exist for the field [user_detail.ID]. Only one may be defined as writable, all others must be specified read-only.
If the ID in UserAccount is both a primary key and a foreign key, then you should declare it as a single field and map it appropriately. Like this:
#Entity
public class UserAccount implements Serializable {
#Id
#OneToOne(mappedBy="userAccount")
private UserDetail userDetails;
}
Or else using #MapsId.
However, i suspect that what you really want is a single class spread over two tables:
#Entity
#Table(name = "user_account")
#SecondaryTable(name = "user_detail")
public class User implements Serializable {
#Id
private int id;
private String email;
private String password;
#Column(table = "user_detail")
private String name;
#Column(table = "user_detail")
private String city;
}
You cannot have both #Id private Integer id; and #JoinColumn(name="id"), you must remove one of them: I doubt that you really need a primary key in the details, so just remove the #Id line from there.