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  • copy child collection to another object

    - by Bogdan
    Hi everyone, I have a one-to-many relationship between Part and Params (a "Part" has many "Params). I'm trying to do something naive like this: Part sourcePart = em.find(Part.class, partIdSource); Part destPart = em.find(Part.class, partIdDest); Collection<Param> paramListSource = sourcePart.getParamList(); destPart.setParamList(paramListSource); Basically I want to copy all the parameters from sourcePart to destPart. Hopefully the persistence provider will automatically set the right foreign keys in the Param table/entity. The above code will obviously not work. Is there any easy way of doing this, or do I have to do create a new collection, then add each Param (creating new Param, setting attributes, etc) ?

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  • Hibernate one to one with multiple columns

    - by Erdem Emekligil
    How can i bind two columns, using @OneToOne annotation? Lets say I've 2 tables A and B. Table A: id1 (primary key) id2 (pk) other columns Table B: id1 (pk) id2 (pk) other columns In class A i want to write something like this: @OneToOne(fetch = FetchType.EAGER, targetEntity = B.class) @JoinColumn(name = "id1 and id2", referencedColumnName = "id1 and id2") private B b; Is it possible to do this using annotations? Thanks.

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  • Pros & Cons: Hibernate vs. EJB 3

    - by Zack
    What are the advantages and disadvantages of Hibernate & EJB3 relative to each other? I found this post, but it didn't really address my question. If I don't have any particular tie to either technology, what would cause me to pick one over the other? Or are there situations where I would want to use both? Thanks, Zack

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  • user height and weight in sql

    - by Samuel
    We are planning to capture a user's height and weight and am looking for ideas on representing them in sql. I have the following questions in mind weight can be expressed in kilograms and grams and height in meters and centimeters, so should I capture them as a BigDecimal with an appropriate precision and scale or capture them as vanilla strings and do the manipulation in the user interface. Note: I am planning to capture the kilograms and grams separately in the user interface. should the metric of measurement be part of the sql (i.e. the end user might want to view this information in pounds, inches according to his preference) OR Should I just support kilograms / meters in the database and do the conversion while showing this in the user interface

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  • how to force ejb3 to reload value from data base and not use those of the context

    - by Kohan95
    Hello here I have a big problem that I hope to find help here I have two entities @Entity @Inheritance(strategy=InheritanceType.JOINED) @DiscriminatorColumn(name="Role", discriminatorType=DiscriminatorType.STRING) public class Utilisateur implements Serializable { private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name="id") private Long id; @Column(name="nom",nullable=false) private String nom; @Column(name="Role",nullable=false, insertable=false) private String Role ; //... } @Entity @Table(name="ResCom") @DiscriminatorValue("ResCom") public class ResCom extends Utilisateur { /... } the first thing I do ResCom rsCom= new ResCom(nom,prenom, email,civilite, SysQl.crypePasse(pass)); gr.create(rsCom); I check my database I see that property is ResCom insert but when I check the value of role I get null Utilisateur tets= gr.findByEmail(email); message=tets.getEmail()+" and Role :"+tets.getRole()+""; but in my bass it ResCom !!!!! the problem disappears when I deploy the project again I hope you have a solution And thank you in advance sorry for my English

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  • after assembling jar - No Persistence provider for EntityManager named ....

    - by alabalaa
    im developing a standalone application and it works fine when starting it from my ide(intellij idea), but after creating an uberjar and start the application from it javax.persistence.spi.PersistenceProvider is thrown saying "No Persistence provider for EntityManager named testPU" here is my persistence.xml which is placed under meta-inf directory: <persistence-unit name="testPU" transaction-type="RESOURCE_LOCAL"> <provider>org.hibernate.ejb.HibernatePersistence</provider> <class>test.model.Configuration</class> <properties> <property name="hibernate.connection.username" value="root"/> <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/> <property name="hibernate.connection.password" value="root"/> <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/test"/> <property name="hibernate.show_sql" value="true"/> <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLInnoDBDialect"/> <property name="hibernate.c3p0.timeout" value="300"/> <property name="hibernate.hbm2ddl.auto" value="update"/> </properties> </persistence-unit> and here is how im creating the entity manager factory: emf = Persistence.createEntityManagerFactory("testPU"); im using maven and tried the assembly plug-in with the default configuration fot it, i dont have much experience with assembling jars and i dont know if im missing something, so if u have any ideas ill be glad to hear them

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  • How to find the entity with the greatest primary key?

    - by simpatico
    I've an entity LearningUnit that has an int primary key. Actually, it has nothing more. Entity Concept has the following relationship with it: @ManyToOne @Size(min=1,max=7) private LearningUnit learningUnit; In a constructor of Concept I need to retrieve the LearningUnit with the greatest primary key. If no LearningUnit exists yet I instantiate one. I then set this.learningUnit to the retrieved/instantied. Finally, I call the empty constructor of Concept in a try-catch block, to have the entitymanager do the cardinality check. If an exception is thrown (I expect one in the case that already another 7 Concepts are referring to the same LearningUnit. In that case, I case instantiate a new LearningUnit with a new greater primary key. Please, also point out, if any, clear pitfalls in my outlined algorithm above.

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  • Annotations: methods vs variables

    - by Zenzen
    I was always sure (don't know why) that it's better to add annotations to variables, but while browsing the Hibernate doc http://docs.jboss.org/hibernate/stable/annotations/reference/en/html_single/#entity-hibspec-collection I noticed they tend to annotate the methods. So should I put my annotations before methods, like this: @Entity public class Flight implements Serializable { private long id; @Id @GeneratedValue public long getId() { return id; } public void setId(long id) { this.id = id; } } Or is it better to do it like this: @Entity public class Flight implements Serializable { @Id @GeneratedValue private long id; public long getId() { return id; } public void setId(long id) { this.id = id; } } Or maybe there's no difference?

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  • is opening and closing of factory contolled by web.xml?

    - by akshay
    This post is related to post InvalidStateException while trying to enter data into DB. Do i need to put some entries in web.xml?Does web.xml control opening and closing of factory?I saw folloing entries in web.xml of another similar project . <resource-ref> <res-ref-name>jms/XYConnectionFactory</res-ref-name> <res-type>javax.jms.ConnectionFactory</res-type> <res-auth>Container</res-auth> <res-sharing-scope>Unshareable</res-sharing-scope></resource-ref> <resource-env-ref> <resource-env-ref-name>rep/xyAppConfig</resource-env-ref-name> <resource-env-ref-type>java.util.Map</resource-env-ref-type></resource-env-ref> What does this entries do?

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  • em.createQuery keeps returning null

    - by Developer106
    I have this application which i use JSF 2.0 and EclipseLink, i have entities created for a database made in MySQL, Created these entities using netbeans 7.1.2, it gets created automaticly. Then i use session beans to work with these entities, the thing is the em.createQuery always returns a null, though I checked NamedQueries in the entities and they perfectly match a sample from the entities named queries:- @NamedQueries({ @NamedQuery(name = "Users.findAll", query = "SELECT u FROM Users u"), @NamedQuery(name = "Users.findByUserId", query = "SELECT u FROM Users u WHERE u.userId = :userId"), @NamedQuery(name = "Users.findByUsername", query = "SELECT u FROM Users u WHERE u.username = :username"), @NamedQuery(name = "Users.findByEmail", query = "SELECT u FROM Users u WHERE u.email = :email"), notice how i use this findByEmail query in the session bean :- public Users findByEmail(String email){ em.getTransaction().begin(); String find = "Users.findByEmail"; Query query = em.createNamedQuery(find); query.setParameter("email", email); Users user = (Users) query.getSingleResult(); but it always returns null from this em.createNamedQuery, i tried using .createQuery first but it also was no good. the stacktrace of the exception Caused by: java.lang.NullPointerException at com.readme.entities.sessionBeans.UsersFacade.findByEmail(UsersFacade.java:48) at com.readme.user.signup.SignupBean.checkAvailability(SignupBean.java:137) at com.readme.user.signup.SignupBean.save(SignupBean.java:146) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) What Seems To Be The Problem Here ?

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  • Large number of tables and Hibernate memory consumption

    - by Vedran
    I'm working on a large ERP project which has database model with about 2100 tables. With "only" 500 tables mapped with Hibernate, application deployed on the web server takes about 3GB of working memory. Is there any way to reduce Hibernate's metamodel memory footprint when using that many tables in one persistence unit? Or should I just give up on ORMs and go with plain old JDBC (or even jOOQ)? Right now I'm using Hibernate 4.1.8, Spring 3.1.3, JBoss AS 7.1 and working with MSSQL database. Edit: JavaMelody memory histogram output - with 2000 generated test tables that are a bit smaller in scope from the original db model (hence 'only' 1.3GB of spent memory)

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  • How to generate entities with Objects?

    - by 01
    I want to generate @Enities with seam-gen from existing database. However its generates very simple version only. For Example @Entity @Table(name = "badges") public class Badges implements java.io.Serializable { private Integer id; private **Integer userId**; private String name; private String date; I want him to generate @Entity @Table(name = "badges") public class Badges implements java.io.Serializable { private Integer id; private **User user**; private String name; private String date; I even have constrain on userId and it points to column User.id P.S. Im using MySQL5 and seam gen is using hbm2java to generate entities.

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  • How to change Hibernate´s auto persistance strategy

    - by Kristofer Borgstrom
    I just noted that my hibernate entities are automatically persisted to the database (or at least to cache) before I call any save() or update() method. To me this is a pretty strange default behavior but ok, as long as I can disable it, it´s fine. The problem I have is I want to update my entity´s state (from 1 to 2) only if the entity in the database still has the state it had when I retrieved [1] (this is to eliminate concurrency issues when another server is updating this same object). For this reason I have created a custom NamedQuery that will only update the entity if state is 1. So here is some pseudo-code: //Get the entity Entity item = dao.getEntity(); item.getState(); //==1 //Update the entity item.setState(2); //Here is the problem, this effectively changes the state of my entity braking my query that verifies that state is still == 1. dao.customUpdate(item); //Returns 0 rows changes since state != 1. So, how do I make sure the setters don´t change the state in cache/db? Thanks, Kristofer

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  • I have a feeling that adding fields marked with @Transient annotation to entity is very bug-prone. A

    - by Roman
    I have some philosophical feeling that adding to an entity fields which doesn't mapped to the DB is a wrong way of solving problems. But are there any concrete situations where using @Transient fields leads to implicit and hard fixing problems? For example, is it possible that adding/removing 2nd level cache will break our app when there are @Transient fields in our entities?

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  • How to load an entity by a key other than primary key?

    - by stacker
    In a customized servlet (seam 2.1.2) this works fine TableNameHome tableNameHome = (TableNameHome) Component.getInstance( "tableNameHome " ); tableName entity = tableNameHome.getInstance(); entity.setXXX(); tableNameHome.persit(); However this one fails: entityManager = tableNameHome .getEntityManager(); Query query = entityManager.createQuery( "SELECT b FROM tablename b WHERE b.box_id = :key2nd" ); query.setParameter( "key2nd", value); List results = query.getResultList(); and leads to this error message: org.hibernate.hql.ast.QuerySyntaxException: tablename is not mapped [SELECT b FROM tablename b WHERE b.key2nd = :key2nd] In EJB 2.1 I could implement other finder-methods. EntityHome.find() searches only by primary key. What do I need to do in order to query by a different criteria than primary key?

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  • Hibernate one-to-one: getId() without fetching entire object

    - by Rob
    I want to fetch the id of a one-to-one relationship without loading the entire object. I thought I could do this using lazy loading as follows: class Foo { @OneToOne(fetch = FetchType.LAZY, optional = false) private Bar bar; } Foo f = session.get(Foo.class, fooId); // Hibernate fetches Foo f.getBar(); // Hibernate fetches full Bar object f.getBar().getId(); // No further fetch, returns id I want f.getBar() to not trigger another fetch. I want hibernate to give me a proxy object that allows me to call .getId() without actually fetching the Bar object. What am I doing wrong?

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  • trying to run a named query

    - by dora
    hi, I’m doing the following: @Entity @SqlResultSetMapping(name="getxxxx", entities=@EntityResult(xxxx.class, fields = { @FieldResult(name="x1", column = "x1"), @FieldResult(name="x2", column = "x2")})) @NamedNativeQuery(name=" getxxxx ", query="select x1, x2 from yyyy", resultSetMapping=" getxxxx ") } )public class xxxx{ . . . public xxxx() { } i get an error: "Table "xxxx" cannot be resolved", the class xxxx is not a table mapped into my source, I’m trying to query the DB and return the results into my class is it possible?

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  • What's the reason behind the jumping GeneratedValue(strategy=GenerationType.TABLE) when not specifyi

    - by joeduardo
    Why do I need to add allocationSize=1 when using the @TableGenerator to ensure that the id wouldn't jump from 1, 2,... to 32,xxx, 65,xxx,... after a jvm restart? Is there a design reason for the need to specify the allocationSize? This snippet would produce the jumping ids @Id @GeneratedValue(strategy = GenerationType.TABLE) private Long id; Here's the modified snippet that produces the properly sequenced ids @Id @GeneratedValue(strategy = GenerationType.TABLE, generator = "account_generator") @TableGenerator(name = "account_generator", initialValue = 1, allocationSize = 1) private Long id;

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  • How to persist every new entity?

    - by simpatico
    I expect every instantiated entity to correspond to a tuple (& co) in the database. In the examples I see around, one always instantiates the entity (via a constructor) and then calls persist with that entity. I find this error-prone, and was wondering if it wasn't possible to have every instantiated entity automatically managed/persisted/reflected to the database (at least intended to). This also seems to prevent me from persisting instance variable entities. I.e. I've an entity which instantiates another (entities it has an association with) in its constructor.

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  • problem in deleting record

    - by akshay
    I have a entity manager em1 .em1 starts a transcation tx on db1 table1.Now inside tx i call a API getdata().This API creastes a new entitymanger em2 and return 1 record.Now if entity manger em1 tries to delete the record returned by em1 , it hangs.Code times out.Is the record locked by em1.How can ii solve this problem? create em1 //em1 start transcation tx1 tx1.start Object r = getData(); em1 tried to delete r //code hangs here tx1.commit Object getData(){ create em2 return data found using em2 }

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