Top "Orm" questions

Object-relational mapping (ORM) is a technique for mapping object-oriented systems to relational databases.

What is an Object-Relational Mapping Framework?

As the title says; what is a ORM framework and what is it useful for?

orm
When and why JPA entities should implement the Serializable interface?

The question is in the title. Below I just described some of my thoughts and findings. When I had a …

java hibernate serialization orm jpa
Hibernate hbm2ddl.auto, possible values, and what they do

I am looking at the Hibernate hbm2ddl.auto configuration property and its possible values: validate update create create-drop What …

hibernate orm properties hbm2ddl
What are detached, persistent and transient objects in hibernate?

What are detached, persistent and transient objects in hibernate? Please explain with an example.

java hibernate orm
Why does Hibernate require no argument constructor?

The no-argument constructor is a requirement (tools like Hibernate use reflection on this constructor to instantiate objects). I got this …

java hibernate orm factory-pattern
session.connection() deprecated on Hibernate?

We need to be able to get the associated java.sql.Connection of a hibernate session. No other connection will …

java hibernate orm
Hibernate throws strange error: Class is not mapped

this is the error org.hibernate.hql.ast.QuerySyntaxException: Payment is not mapped [select p from Payment p] I don't …

java hibernate jpa orm hibernate-mapping
How to turn off hbm2ddl?

I couldn't find a reference on how to switch hbm2ddl off.

java hibernate orm hbm2ddl
How to solve the LazyInitializationException when using JPA and Hibernate

I am working on a project for a customer who wants to use lazy initialization. They always get "lazy initialization …

java hibernate jpa orm lazy-initialization
Eclipse does not recognize content of persistence.xml

Im getting the following error in eclipse: The persistence.xml file does not have recognized content. My persistence.xml file …

java eclipse orm jpa m2eclipse