jpa

问题 I have a User, an Ad, and a table Follows that show who follows who. What I need to do is I need to implement a button that on clicked (and being loged in) regsiters that follow on the Follows table, and them you need to be able to show just de Ads ofthe people you follow (Currently there's only a view of ALL the ads, and now I need to make one that just shows the one that have been posted by the users I follow) Any ideas of how can I make that possible? AdRepository: @Repository public

问题 I was looking for documentation or answer how will the cascade work for child of child , example : public class Parent{ @OneToMany(fetch = FetchType.EAGER,mappedBy = "parent",cascade = CascadeType.ALL) private List<Child> child; } public class Child{ @OneToMany(mappedBy="child") private List<AnotherChild> anohterChild; } @ManyToOne private Parent parent; } now the question, will the cascade operation applied on "Child" from parent class apply to "AnotherChild" ? in other words if I persist

问题 I have an existing postgres database with the database "testdb" and the database schema testdbschema". If I use the default persistence.xml configuration of RESOURCE_LOCAL the following property is working: <property name="javax.persistence.jdbc.url" value="jdbc:postgresql://server:port/testdb?currentSchema=testdbschema" /> I want to configure my database connection within my web.xml as a data-source. Everything is working well, except the configuration of the database schema. Here is my web

问题 I have this entity, called FatRabbitCarrot: @Entity public class FatRabbitCarrot { private Long id; private FatRabbit fatRabbit; private Carrot carrot; @Id @Column(name = "id", nullable = false) @GeneratedValue(strategy = GenerationType.IDENTITY) public Long getId() { return id; } public void setId(Long id) { this.id = id; } @ManyToOne @JoinColumn(name = "fatRabbit_id", foreignKey = @ForeignKey(name = "FK_FatRabbitCarrot_fatRabbit")) public FatRabbit getFatRabbit() { return fatRabbit; }

问题 I'm rewriting a big project with SpringBoot 2.2.6 and I'm run into a problem. In the old project (pure ejb ) when a complex entity is updated, the code build entity from DTO's as follows: public Entity dtoToEntity(DTO dto) { Entity entity = new Entity(); entity.setId(dto.getID()); // ecc... // ecc... entity.setSubEntity(dto.getSubEntity() != null ? new SubEntity(dto.getSubEntity().getId() : null); // and so on } The important section is that related to subentity! After made a mapping like

问题 I have the below persistence file - <persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"> <persistence-unit name="unit" > <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider> <properties> <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" /> <property name=

问题 I have the below persistence file - <persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"> <persistence-unit name="unit" > <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider> <properties> <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" /> <property name=

问题 I have a class "Branch". Either classes "Dictionary" and "Link" which I want to use as < T> here. @Entity public class Branch<T> { ... @OneToMany(mappedBy = "branch", orphanRemoval = true, cascade = CascadeType.ALL) private List<T> entities = new ArrayList<>(); } It throws a Runtime Exception: org.hibernate.AnnotationException: Property by.ipps.accounting.model.Branch.branches has an unbound type and no explicit target entity. Resolve this Generic usage issue or set an explicit target

问题 For several days I'm trying to manage with JPA transactions after moving to WildFly 8 server and JEE7 and I cannot understand why in some cases @Transactional (javax.transaction.Transactional) annotation doesn't intercept method annotated with it. I cannot see any rule why sometimes it works and sometimes not. Example of my not working code: import javax.inject.Inject; import javax.inject.Named; import javax.persistence.EntityManager; import javax.faces.view.ViewScoped; import com.i4u.app

问题 Entity Survey: @Entity @Table(name = "Survey") public class Survey implements Serializable { private Long id; private String name; private String address; private List<Question> questions; @Id @Column(name = "id") public Long getId() { return id; } @Column(name = "name") public String getName() { return name; } @Column(name = "address") public String getAddress() { return address; } @OneToMany(fetch = FetchType.LAZY, mappedBy = "survey") public List<Question> getQuestions() { return questions