Setting default values for columns in JPA
Is it possible to set a default value for columns in JPA, and if, how is it done using annotations? 20 Answers 20
jpa
Hibernate SessionFactory vs. JPA EntityManagerFactory
I am new to Hibernate and I’m not sure whether to use a Hibernate SessionFactory or a JPA EntityManagerFactory to create a Hibernate Session. What is the difference between these two? What are the pros & cons of using each of those? 8 Answers 8
What is the difference between Hibernate and Spring Data JPA
What are the main differences between Hibernate and Spring Data JPA? When should we not use Hibernate or Spring Data JPA? Also, when may Spring JDBC template perform better than Hibernate / Spring Data JPA? 6 Answers 6
PersistentObjectException: detached entity passed to persist thrown by JPA and Hibernate
I have a JPA-persisted object model that contains a many-to-one relationship: an Account has many Transactions. A Transaction has one Account. Here’s a snippet of the code: @Entity public class Transaction { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @ManyToOne(cascade = {CascadeType.ALL},fetch= FetchType.EAGER) private Account fromAccount; …. @Entity public class Account { @Id @GeneratedValue(strategy = … Read more
org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when ‘hibernate.dialect’ not set
I am trying run a spring-boot application which uses hibernate via spring-jpa, but i am getting this error: Caused by: org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when ‘hibernate.dialect’ not set at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.determineDialect(DialectFactoryImpl.java:104) at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.buildDialect(DialectFactoryImpl.java:71) at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:205) at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111) at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234) at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206) at org.hibernate.cfg.Configuration.buildTypeRegistrations(Configuration.java:1885) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1843) at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:850) at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:843) at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:398) at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:842) … Read more
Why does JPA have a @Transient annotation?
Java has the transientkeyword. Why does JPA have @Transient instead of simply using the already existing java keyword? 8 Answers 8
What is the easiest way to ignore a JPA field during persistence?
I’m essentially looking for a “@Ignore” type annotation with which I can stop a particular field from being persisted. How can this be achieved? 10 Answers 10
The JPA hashCode() / equals() dilemma
There have been some discussions here about JPA entities and which hashCode()/equals() implementation should be used for JPA entity classes. Most (if not all) of them depend on Hibernate, but I’d like to discuss them JPA-implementation-neutrally (I am using EclipseLink, by the way). All possible implementations are having their own advantages and disadvantages regarding: hashCode()/equals() … Read more
Create the perfect JPA entity [closed]
Closed. This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed 8 years ago. Improve this question I’ve been working with JPA (implementation Hibernate) for some time now and each time I need … Read more
Hibernate throws MultipleBagFetchException – cannot simultaneously fetch multiple bags
Hibernate throws this exception during SessionFactory creation: org.hibernate.loader.MultipleBagFetchException: cannot simultaneously fetch multiple bags This is my test case: Parent.java @Entity public Parent { @Id @GeneratedValue(strategy=GenerationType.IDENTITY) private Long id; @OneToMany(mappedBy=”parent”, fetch=FetchType.EAGER) // @IndexColumn(name=”INDEX_COL”) if I had this the problem solve but I retrieve more children than I have, one child is null. private List<Child> children; } … Read more
