I have two entities using a OneToMany and ManyToOne relationship:
#Entity
#Table(name = TableName.PERSON)
public class Person {
#Id
#Column(name = FieldName.DB_KEY)
public String dbKey;
#Column(name = FieldName.ENTITY_ID)
public String entityId;
#Column(name = FieldName.SORT_KEY)
public String sortKey;
#JoinColumn(name = FieldName.ENTITY_ID, referencedColumnName =
FieldName.ENTITY_ID, insertable = false, updatable = false)
#ManyToOne(fetch = FetchType.EAGER)
#JoinFetch(value = JoinFetchType.INNER)
public WLEntity entity;
}
#Entity
#Table(name = TableName.WL_ENTITY)
public class WLEntity {
#Id
#Column(name = FieldName.ENTITY_ID)
public String entityId;
#Column(name = FieldName.HAS_ADDRESS)
public boolean hasAddress;
#OneToMany(mappedBy = "entity", targetEntity = PersonIndex.class, cascade = CascadeType.ALL)
public List<Person> persons;
}
And a JPA-Repository defining one findBy... Method:
#Repository
public interface PersonRepository extends JpaRepository<Person, String> {
List<Person> findBySortKeyStartingWith(String sortKey);
}
If I call this method I can see in the console:
SELECT t1.DB_KEY, t1.ENTITY_ID, t1.SORT_KEY, t0.ENTITY_ID, t0.HAS_ADDRESS FROM WL_ENTITY t0, PERSON t1 WHERE (t1.SORT_KEY LIKE ? AND (t0.ENTITY_ID = t1.ENTITY_ID))
So the join I want is correct executed, but in the returned data the entity field is still null but all other fields are filled:
List<Person> persons = personRepository.findBySortKeyStartingWith("Sort");
Person person = persons.get(0);
person.entity == null but person.entityId is correctly filled.
So what I have to do, to get person.entity filled?
I use spring boot with eclipselink jpa 2.6.4
Related
I want to do select like this in my jpa spring repository
SELECT sicknes_id, count(symptomp_id) as ilosc FROM symptomp_sicknes where symptomp_id IN (1,2) group by sicknes_id Order by ilosc DESC;
My enitity
#Entity
#Table(name = "symptomp")
public class Symptomp {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "symptomp_id")
private Long symptomp_id;
#Column(name = "name")
private String name;
#Column(name = "description")
private String description;
#ManyToMany(cascade = {CascadeType.DETACH,CascadeType.MERGE,CascadeType.PERSIST,CascadeType.REFRESH}, fetch = FetchType.LAZY)
#JoinTable(name = "symptomp_sicknes",joinColumns = #JoinColumn(name = "symptomp_id"),inverseJoinColumns = #JoinColumn(name = "sicknes_id"))
private Set<Sicknes> sicknes = new HashSet<>();
#Entity
#Table(name = "sicknes")
public class Sicknes {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "sicknes_id")
private Long sicknes_id;
#Column(name = "name")
private String name;
#Column(name = "description")
private String description;
#ManyToOne(cascade = {CascadeType.DETACH,CascadeType.MERGE,CascadeType.PERSIST,CascadeType.REFRESH}, fetch = FetchType.LAZY)
#JoinColumn(name = "speciesId")
private Species species;
My Symptomp repository:
public interface SymptompRepository extends JpaRepository<Symptomp, Long> {
#Query("select p from Symptomp p where name like ?1%")
public List<Symptomp> findAllBySymptompName(String symptomp);
public Symptomp findByName(String symptomp);
public List<Symptomp> findByNameIn(List<String> list);
Integer countDistinctSymptompByName(String id);
}
How I can create this select in my JPA repository?
I try get value like in select but i got error mapping bean.
You can get query result as List<Object[]> using nativeQuery=true parameter
#Query("SELECT sicknes_id, count(symptomp_id) as ilosc FROM symptomp_sicknes where symptomp_id IN (1,2) group by sicknes_id Order by ilosc DESC", nativeQuery=true)
List<Object[]> getQueryResult();
Other option is to create dto class with appropriate constructor
public class QueryResultDto {
Long sicknesId;
Long count;
public QueryResultDto(Long sicknesId, Long count) {
this.sicknesId = sicknesId;
this.count = count;
}
}
Then using JPQL
#Query("select new yourproject.dtopath.QueryResultDto(...")
List<QueryResultDto> getQueryResult(#Param("symptompIds") List<Long> symptompIds);
If you want to avoid a native Query the best way is to create an Entity for that JoinTable. Then you can query it easily. Additional benefit if this is that if in future a requirement will pop up that you have to store additional attributes in that relation you will have the Entity already there to do that easily.
I use spring boot, with jpa (hibernate) and postgresql
I use composite key.
#Entity
#IdClass(SamplingsPK.class)
#Inheritance(strategy = InheritanceType.SINGLE_TABLE)
public class Samplings {
#Id
#GeneratedValue
private Integer id;
#Id
private int year;
#OneToMany(mappedBy = "sampling", cascade = CascadeType.ALL, orphanRemoval = true)
private List<Samples> samples = new ArrayList<>();
...
}
public class SamplingsPK implements Serializable {
private Integer id;
private int year;
public SamplingsPK(Integer id, int year) {
this.id = id;
this.year=year;
}
private SamplingsPK(){
}
#PrePersist
public void prePersist() {
year = LocalDate.now().getYear();
}
}
#Entity
public class Samples {
#Id
#SequenceGenerator(name = "samples_id_seq", sequenceName = "samples_id_seq", allocationSize = 1)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "samples_id_seq")
private Integer id;
private String sampleLetter;
#ManyToOne
#JoinColumns({
#JoinColumn(name = "sampling_id", referencedColumnName = "id"),
#JoinColumn(name = "sampling_year", referencedColumnName = "year")
})
private Samplings sampling;
}
That work fine
Instead of having an sequence in samples, I would like to have a composite key... SamplingsPK + sampleLetter.
Is it possible to do it, how to save a sample?
This is a "derived identity", so Samples could be mapped with an #IdClass like this:
#Entity
#IdClass(SamplesPK.class)
public class Samples {
#Id
#ManyToOne
#JoinColumns({
#JoinColumn(name = "sampling_id", referencedColumnName = "id"),
#JoinColumn(name = "sampling_year", referencedColumnName = "year")
})
private Samplings sampling;
#Id
private String sampleLetter;
}
public class SamplesPK {
SamplingsPK sampling; // matches name of attribute and type of Samplings PK
String sampleLetter; // matches name and type of attribute
}
Derived identities are discussed (with examples) in the JPA 2.2 spec in section 2.4.1.
I am having an issue in setting up a many to many relationship in my entities. And I don't understand why
failed; nested exception is org.hibernate.AnnotationException: mappedBy reference an unknown target entity property: cardgame.bean.User.card in cardgame.bean.Card.users
My Entities:
#MappedSuperclass
#Data
public class BaseEntity implements Serializable {
#Id
#Column(name = "id", nullable = false, unique = true)
private String id;
public BaseEntity() {
this.id = UUID.randomUUID().toString();
}
}
My user emtity:
#Data
#Entity
#Table(name = "users")
public class User extends BaseEntity {
#Column(name = "username", nullable = false, unique = true)
private String username;
#Column(name = "uuid", nullable = false)
private String uuid;
#Column(name = "email", nullable = false, unique = true)
private String email;
#OneToMany(mappedBy = "user", fetch = FetchType.LAZY, cascade = CascadeType.ALL, orphanRemoval = true)
private List<Card> cards;
#Column(name = "isActive", nullable = false)
private boolean isActive;
}
My card entity:
#Data
#Entity
#Table(name = "cards")
public class Card extends BaseEntity {
#OneToMany(mappedBy = "card")
private List<User> users;
#Column(name = "strength", nullable = false)
private int strength;
#Column(name = "isActive", nullable = false)
private boolean isActive;
}
The users and cards tables have a many-to-many relationship via user_card table:
#Data
#Entity
#Table(name = "user_card")
public class UserCard implements Serializable {
#Id
#ManyToOne
#JoinColumn(name = "user_id", nullable = false)
private User user;
#Id
#ManyToOne
#JoinColumn(name = "card_id", nullable = false)
private Card card;
#Column(name = "cardCount", nullable = false)
private int cardCount;
}
What am i doing incorrect. Please help me
I have a large DB on MySql Workbench and I'm trying to map the relationship between the entities on Eclipse Mars thanks to Hibernate and the JPA module. The fact is that I receive the error:
"In attribute 'personAddresses', the "mapped by" attribute 'peopleAdd' has an invalid mapping type for this relationship."
This are the entities involved.
1
I've to say that making a forward engineering, Hibernate creating for me an AddressId class, where the composite primary key of Address is mapped. I suspect that the problem could be this, but I'm not certain, can you help me please?
Under I post the code so that it's more clear to understand how the classes are implemented.
#Entity
#IdClass(AddressId.class)
#Table(schema = "YouDroop", name = "Address")
public class Address implements Serializable
{
...
private Collection<Person> peopleAdd = new HashSet<Person>();
#Id
#Column(name = "Address", length = 45, unique = true, nullable = false)
private String address;
#Id
#Column(name = "Number", unique = true, nullable = false)
private int number;
...
#ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
#JoinTable(
name = "PersonHasAddress",
joinColumns = {
#JoinColumn(name = "Address_Address", referencedColumnName = "Address", nullable = false),
#JoinColumn(name = "Address_Number", referencedColumnName = "Number", nullable = false)
},
inverseJoinColumns = {#JoinColumn(name = "Person_Email", referencedColumnName = "Email", nullable = false)}
)
public Collection<Person> getPeopleAddressed(){
return this.peopleAdd;
}
public void setPeopleAddressed(Collection<Person> people){
this.peopleAdd = people;
}
}
public class AddressId implements Serializable
{
private String address;
private int number;
public AddressId(){}
public AddressId(String address, int number) {
super();
this.address = address;
this.number = number;
}
...
}
#Entity
#Table(name = "Person", schema = "YouDroop", uniqueConstraints =
{ #UniqueConstraint(columnNames = "NickName"),
#UniqueConstraint(columnNames = "Password") })
public class Person implements Serializable
{
...
private Collection<Address> addresses = new HashSet<Address>();
...
#ManyToMany(fetch = FetchType.LAZY, mappedBy = "peopleAdd")
public Collection<Address> getPersonAddresses(){
return this.addresses;
}
public void setPersonAddresses(Collection<Address> addresses){
this.addresses = addresses;
}
}
Since you placed you #ManyToMany annotation on your getter method (or property) and not on the field. The mappedBy attribute should reference the property instead and not the field.
#ManyToMany
public Collection<Person> getPeopleAddressed() {
...
}
So your mappedBy attribute should have been
#ManyToMany(mappedBy="peopleAddressed")
public Collection<Address> getPersonAddresses() {
...
}
I have three database tables: Customer, Product and PurchaseOrder (for mapping). I am using openjpa for peristence in java rest application.
To all of the tables I have corresponding entities:
Customer
#Entity
#Table(name = "customer")
#XmlRootElement
#NamedQueries({...})
public class Customer implements Serializable {
...
#OneToMany(cascade = CascadeType.ALL, mappedBy = "customerId")
private Collection<PurchaseOrder> purchaseOrderCollection;
Product
#Entity
#Table(name = "product")
#XmlRootElement
#NamedQueries({...})
public class Product implements Serializable {
...
#OneToMany(cascade = CascadeType.ALL, mappedBy = "productId")
private Collection<PurchaseOrder> purchaseOrderCollection;
PurchaseOrder
#Entity
#Table(name = "purchase_order")
#XmlRootElement
#NamedQueries({..})
public class PurchaseOrder implements Serializable {
...
#Id
#Basic(optional = false)
#Column(name = "order_num")
private Integer orderNum;
#JoinColumn(name = "customer_id", referencedColumnName = "customer_id")
#ManyToOne(optional = false)
private Customer customer;
#JoinColumn(name = "product_id", referencedColumnName = "product_id")
#ManyToOne(optional = false)
private Product product;
What is the best way to get all the customers who ordered a product with specific id?
I could create namedQuery, I could build criteria with joins etc. But i think there could be a better way how to make use of the mapping entity (what would be point of this entity otherway?). Something like setting the productId to the purchaseOrder entity and then fetch all the customers via purchaseOrderCollection in customer entity? But i cannot figure it out. Is there other way than custom/named query or criteria building?
Thanks.
ok I figured it out, it can be this way
long productId = //get the id
Product product = entityManager.find(Product.class, productId);
Collection<PurchaseOrder> purchaseOrderCollection = product.getPurchaseOrderCollection();
if (purchaseOrderCollection != null) {
List<Integer> customers = new ArrayList<>(product.getPurchaseOrderCollection().size());
for (PurchaseOrder purchaseOrder : product.getPurchaseOrderCollection()) {
customers.add(purchaseOrder.getCustomerId());
}
return customers;
} else {
return Collections.EMPTY_LIST; // or null;
}
feel free to offer better sollution :)