hibernate

Hibernate recursive query

My desired query is to get a list of Course objects that belong to a Category. My objects are as follows: public class Course{ String name; List<Category> categories; } public class Category{ String name; Category parent; } Since the categories reference each other, they can have an infinite depth: A A.A ...

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 work, as this connection may be associated with a running transaction. If session.connection() is now deprecated, how am I supposed to do that? Thanks, -Sergio ...

Hibernate HBM one-to-many

I have a one-to-many relationship and in my HBM I want to include the association for delete purposes. How can I express that without query/loading the related table/object? Just including a bag or another collection is the obvious answer, but is there something else? Hibernate 2.2 ...

Hibernate composite key which are foreigen key to another table

Hello All, I have two table Part and SubPart. Part table has general fields like id, name, desc etc. The SubPart table has part_id, sub_part_id as composite key. Both of these columns are referring to Part table and has a one to many mapping for each of them, like for each part_id in the Part table there can be multiple entries in SubPar...

Hibernate - link table with additional columns - saving in one transaction

Hi, I am learning Hibernate and just read the chapter "7.2.3 Adding columns to join tables" of the "Java Persistance with Hibernate" book. My goal is to save Item, Category and CategorizedItem in one transaction. There is a constructor there (page 305): public CategorizedItem(String username, Category category, Item item) { // Set...

Batch load a lazily loaded Hibernate property

Suppose I have a: class Student { int id; String name; List<Course> courses; //Lazily loaded as per Hiberante config } Now suppose I have a List students and in order to optimize fetching List for all these students, I was to batch select them rather than letting Hibernate call a separate SQL one by one. I cannot turn off ...

Spring, multiple Hibernate Sessionfactories configuration

Hi there, I need to set up multiple Sessionfactories in my app, now I'm facing a problem. I can't use the 2nd level cache at the moment because only the cache from the first factory is returned. Providing a hibernate.cache.region_prefix would solve the problem I guess. How can I supply for each factory a own region per Spring XML config...

Oracle Char type and Hibernate

Hi guys, I have a oracle table which contains char(n) type for several columns. I use hibernate tools to create entities objets and this tool map char type in String. But when I deploy my application, I get an error because Hibernate wait a varchar2 type and not a char type: Wrong column type in ARBOR.CMF for column CHG_WHO. Found: ch...

Problem adding @ManyToOne mapping on Non primary-key in SQL Server

I have a problem with changing my spring/hibernate application from MySql to SQL Server. When Hibernate is updating the database by starting the server he want to creates(by hibernate.hbm2ddl.auto set on update ) the database but a foreign-key fails on following error: Unsuccessful: alter table table2 add constraint FKDC2DC97ECEB31922 ...

Hibernate 3.5.5, Second Level Cache Configuration

Hello, After implement Hibernate Monitoring, i have noticed that hibernate execute too much query than it have on the query string table in statistics. Screen-shots of statistics: I think, implement hibernate 2nd level cache and particularly hibernate query cache help me to reduce this amount of query execute. I searched on the web...

unit of work pattern and history

Hi All, In this page: http://docs.jboss.org/hibernate/core/3.3/reference/en/html/transactions.html I have read that: "A unit of work is a design pattern described by Martin Fowler" Did Martin Fowler discovered this pattern before hibernate boys and is Martin the only source of describing this pattern? Regards ...

Creating Indexes on DB with Hibernate @Index Annotation

I have annotation-driven hibernate capabilies on my project. Now I want to create an index over a column. My current column definition is @NotNull @Column(name = "hash") private String hash; and I add @Index annotation here. @NotNull @Column(name = "hash") @Index(name="hashIndex") private String hash; and then DROP TABLE and resta...

What's Wrong with this HQL Query?

With this HQL query: SELECT DISTINCT fs FROM FileStatus fs WHERE UPPER(STR(fs.filePath)) LIKE :FILE_PATH I get: javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: could not execute query at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:637) ...

What is a IncompatibleClassChangeError exception in Java?

Hi, i am working on a small application and I am trying to use Hibernate Annotations to map my entities. I wanted to test if everything is alright when i got this exception : Exception in thread "main" java.lang.ExceptionInInitializerError at fr.cc2i.intervention.dao.main.Main$HibernateUtil.<clinit>(Main.java:48) at fr.cc2i.inter...

Is this a good design in hibernate?

Hi all, i have a parent entity Service and a child ExtendedService in a SINGLE_TABLE inheritance. A third entity ServiceCollector need to include both entites Service and ExtendedService. This is a fixed requirement, and with this design i can realize it using polymorphism. THE PROBLEM: Very often i need to retrieve ONLY the parent cla...

Primitive or wrapper for hibernate primary keys

I've been looking at various hibernate tutorials and samples, for their identity/primary key property, some use a Java primitive type, some uses the wrapper type, that is; private int id; vs private Integer id; Why and when would I use one over the other, for the entity key ? ...

hibernate eagerly load an association that's normally lazy

I have these 2 mappings: <hibernate-mapping> <class name="sample.Operator" table="OPERATOR"> <id name="id" > <generator class="native" /> </id> <property name="name" not-null="true"> <column name="NAME" /> </property> <set name="pointCodes" inverse="false" lazy="true" ...

Persistence deployment issue

I have a hibernate project, which uses JPA. my persistence.xml contents is as follows: <persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"&gt;...

(1+N) selects with OnetoOne associations

Considering the following model: @Entity public class User { @Id @Column(name = "USER_ID") private Long userId; @Column(name = "FIRST_NAME") private String firstName; @Column(name = "LAST_NAME") private String lastName; @OneToOne @PrimaryKeyJoinColumn private UserExt userExt; ... //getters...

JPA Inheritance entitymanager.find produces ClassCastException

Hi, I have a class hierarchy like this: @Entity @Table (name="call_distribution_policies") @Inheritance (strategy=InheritanceType.JOINED) public class CallDistributionPolicy implements Serializable, Cloneable{ ---------------- } @Entity @Table(name="skill_based_call_distribution_policies") public class SkillBasedCallDistributionP...