March 2008 - hibernate-dev - Jboss List Archives

review of a patch for lazy loading of association with property-ref

by Fischer, Lars

Hello list, I would like to use hibernate in a new project but I miss a feature: A mapping like <many-to-one name="RE" column="RE_ID" property-ref="ID" entity-name="RE" lazy="proxy" /> ignores the lazy loading. Looking into the code I found as reason the usage of the property-ref attribute. The project database schema bases on a legacy design which I can't change. Because of that I can not avoid the usage of property-ref. So I tried to get the lazy loading running with property-ref by extending the hibernate core sources. With my changes it is now working for my project, but I do not claim that this would be the best solution, because I have only a rudimental knowledge of the hibernate internals. Is it possible that someone of the experienced developers could take a look on my changes and give me a feedback? I created a patch based on hibernate core 3.2.6.ga. Should I upload it into JIRA or can I post it into this list? regards, Lars ------------------------------------------------------------------------------------------------------------ IBYKUS AG fur Informationstechnologie, Erfurt / HRB 108616 - D-Jena / Vorstand: Helmut C. Henkel, Dr. Lutz Richter / Vorsitzender des Aufsichtsrates: Dr. Frieder Schauble

16 years, 9 months

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Process and requirements for contributing to Hibernate & feature proposal

by Marcin Mościcki

Hi, Some time ago I submitted a minor bug having to do with named sql query mapping/binding ( http://opensource.atlassian.com/projects/hibernate/browse/HHH-3108) and subsequently fixed it. Hibernate page mentions that contributions should be submitted in patch format, but doesn't say to what version / svn tag - I presume last stable one, that is 3.2.6.ga? As I already spent some time debugging and got a basic understanding of the code, I thought I might add some functionality I heavily miss. The question is, is it possible for such a user contribution to make it to be incorporated into the code? If so, what would be the procedure and requirements? My issues with hibernate I'd like to improve concern efficiency and control of fetching whole graphs of objects with many associations: 1. First of all, a possibility of specifying a custom collection loader for fetch='subselect' on a per-query basis. The root query would be able to define a subselect query used to fetch collections owned by returned entities (ideally also nested associations). If original query is complicated (involves joins or subselects), current solution is highly ineffective and I found I could often write optimized queries returning the same data. This is especially pronounced when a large percentage of total data in the table is returned by associated queries. 2. Do some automatic optimization for fetch="subselect". Most notable example is fetching collections defined in subclasses of an entity returned by a polymorphic query. When using table-per-concrete-subclass approach, first query results in an SQL with a couple of joins, and is then used literally as a subselect in the query for associated objects. In most cases it would be sufficient to do the subselect only against the base class table. 3. Allow to use HQL queries as collection loaders, not only SQL queries. I don't know, maybe you're currently working on it - it seems so natural and I've seen a feature request in JIRA. If you'd be interested in such improvements and find them compatible with the project's roadmap, please let me know. I am very enthusiastic about seeing them in hibernate - the lack of 1) pushed us to drop hibernate for a more flexible, low-level solution in some projects having a complicated object model (arguably exactly those which would really benefit from a model-driven persistance approach). Unfortunately, there's no way my company would allow usage of an in-house patched version of hibernate, so my work on such a patch would be mostly a waste of time if it didn't make it to a release one day. Best regards, -- c):-i Marcin Mościcki --------------------------------------------------------------------------------------------------- It is, as far as he knows, the only way of coming downstairs, but sometimes he feels that there really is another way, if only he could stop bumping for a moment and think of it. And then he feels that perhaps there isn't.

16 years, 9 months

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Hibernate EntityManager and Annotations bug fix release

by Emmanuel Bernard

Check it out http://in.relation.to/8711.lace

16 years, 9 months

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invalid URL referenced by Hibernate Tools Eclipse update site

by Frederick C Druseikis

Hello list, Looks like something has changed on release.mozilla.org, possibly in the last few hours. Using Eclipse Europa (on Mac OS X 10.4) the HibernateTools update site installation fails with a dialog stating the following: Update operation has failed Error retrieving "plugins/org.mozilla.xpcom_1.8.1.3-20070904.jar". [Server returned HTTP response code: "404 Not Found" for URL: http://releases.mozilla.org/pub/mozilla.org/xulrunner/releases/1.8.1.3/co.... ] Server returned HTTP response code: "404 Not Found" for URL: http://releases.mozilla.org/pub/mozilla.org/xulrunner/releases/1.8.1.3/co... . The required file now appears to be located at: http://releases.mozilla.org/pub/mozilla.org/xulrunner/releases/1.8.1.3/co.... .. Regards, Fred

16 years, 9 months

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Is this a bug or am I just handling it the wrong way ?

by joël Winteregg

Dear hibernate-dev, After maaaannny googling and after someone told me (through an IRC chat) that this problem could be a bug, I finally come to you.. Explanations are given here: http://forum.hibernate.org/viewtopic.php?p=2379177 This behavior is related to polymorphic Criteria queries using a Table per class hierarchy mapping where a sub-class contains a one-to-many association (Set<UserAddress>). Here is the query and the stack trace: Hibernate: select .... All the attributs ... from User this_ inner join UserAddress useraddress1_ on this_._oid=useraddress1_._user_oid inner join UserAddress useraddress1_ on this_._oid=useraddress1_._user_oid where useraddress1_.street like ? 00:10:52,366 WARN [JDBCExceptionReporter] [main] SQL Error: 0, SQLState: 42712 00:10:52,366 WARN [JDBCExceptionReporter] [main] SQL Error: 0, SQLState: 42712 00:10:52,366 ERROR[JDBCExceptionReporter] [main] ERROR: table name "useraddress1_" specified more than once 00:10:52,366 ERROR[JDBCExceptionReporter] [main] ERROR: table name "useraddress1_" specified more than once Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not execute query at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:67) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43) at org.hibernate.loader.Loader.doList(Loader.java:2223) at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2104) at org.hibernate.loader.Loader.list(Loader.java:2099) at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:94) at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1569) at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:283) at com.netguardians.ngscreener.middleware.simulator.QuerySimulator.Exec(QuerySimulator.java:163) at com.netguardians.ngscreener.middleware.simulator.QuerySimulator.main(QuerySimulator.java:60) Caused by: org.postgresql.util.PSQLException: ERROR: table name "useraddress1_" specified more than once at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:1548) at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1316) at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:191) at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:452) at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:351) at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:255) at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:186) at org.hibernate.loader.Loader.getResultSet(Loader.java:1787) at org.hibernate.loader.Loader.doQuery(Loader.java:674) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:236) at org.hibernate.loader.Loader.doList(Loader.java:2220) ... 7 more I'm using Hibernate 3.2.5.ga. When trying 3.2.6.ga (to see if I get the same result) I get the following problem (I'm using a standalone JTA implementation called BTM): http://opensource.atlassian.com/projects/hibernate/browse/HHH-3109 http://opensource.atlassian.com/projects/hibernate/browse/HHH-3110 For that problem, I think that hint would help me: "Either setup BTM to bind to JNDI or provide an implementation of org.hibernate.transaction.TransactionFactory that uses the purely standalone/in-VM BTM" But that would be the second phase ;-) Could the problem of the polymorphic query be a bug ? Or am I just missing something ? Many thanks in advance for your help and hope to read you soon, Joël

16 years, 9 months

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How to make hibernate load required objects only rather than all available in database

by Prajapati Manish Narandas

Hi all, I am using Hibernate for ORM. Right now i am monitoring my application using JProfiler. Here, i run my application and monitoring instances which are not garbage collected. In one flow of my application, i have found that hibernate is instantiating objects on the basis of available records in corrosponding table. For example, I have tried to load *BaseListing class* which is child of * UserDtls* and when i load BaseListing like as given below (DAO layer code snippet). *baseListing = (BaseListing)getHibernateTemplate().load(BaseListing.* *class, listingId);* Here, it loads *baselisting* with all its containing objects including UserDtls where returned UserDtls object is one but in jprofiler it shows 32 UserDtls allocations (Instance Allocations, *here UserDtls table has 32 records*) whereas in baseListing it has loaded only one instance*.* ** So JProfiler shows me this 32 as a non-GCed objects. Can anybody tell me that why hibernate is loading (creating instances of) UserDtls on the basis of available records into the UserDtls even in baseListing it is assigning one instance of UserDtls. (The mapping files are as given below) i.e I have two classes BaseListing and UserDtls. Following is a configuration snippet of both *BaseListing.hbm.xml* <class name="test.BaseListing" table="base_listing" lazy="false"> ......................... <many-to-one name="userDtls" class="test.UserDtls" lazy="false"> <column name="USER_ID" /> </many-to-one .................... </class> </hibernate-mapping> *UserDtls.hbm.xml* <class name="test.UserDtls" table="user_dtls" lazy="false" > ........................... <set name="baseListings" inverse="true" fetch="select"> <key> <column name="USER_ID" /> </key> <one-to-many class="test.BaseListing" /> </set<key> .................... </class> </hibernate-mapping> Here,can any body tell me how can i make hibernate to load only required 1 instance rather than unnecessary 32 instances of UserDtls. Regards, Manish

16 years, 9 months

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Hibernate Annotations and Hibernate EntityManager in release candidate

by Emmanuel Bernard

Hibernate Annotations 3.3.1.CR1 and Hibernate EntityManager 3.3.2.CR1 are available for testing at http://www.hibernate.org/6.html. There is a ton of bug fixes especially in the Java Persistence scanning area and in edge mappings support. Some minor new features have been added as well (integration with the latest Hibernate Search collection events, @Any, @NaturalId). Check the changelogs at http://opensource.atlassian.com/projects/ hibernate/browse/ANN? report=com.atlassian.jira.plugin.system.project:changelog-panel and http://opensource.atlassian.com/projects/hibernate/browse/EJB? report=com.atlassian.jira.plugin.system.project:changelog-panel Unless sneaky bugs are discovered, these versions will be part of next JBoss AS 5 release. Go check it out. Emmanuel

16 years, 9 months

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Last train for Hibernate Annotations / EntityManager bug fixes

by Emmanuel Bernard

I am in the middle of a fix-athlon for Hibernate Annotations and Hibernate EntityManager. If you think there are bug fixes (not enhancements) that should be part of the upcoming releases, let me know in the next 2 days. especially if (in decreased priority): - the bug is important - there is a patch - there is a test case - the description is clear No guaranty on execution but I might have overlooked important stuffs. Emmanuel

16 years, 9 months

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Re: SVN Tag for 3.2.0.GA? (hibernate-tools)

by Tomislav Stojcevich

This was for hibernate-tools. On Feb 19, 2008 10:07 AM, Tomislav Stojcevich <stojcevicht(a)gmail.com> wrote: > Was a tag created for this release? The closest I can find is CR1, I > need the sources to the GA release. > > > Thanks, > --tom > -- --tom

16 years, 9 months

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[Search] Adding more functionality to ScopedAnalyzer

by Nick Vincent

Hi there, I would like to extend ScopeAnalyzer so that I can specify an analyzer for some extra fields that my custom bridge is writing into the index. I don't (and can't really) create dummy accessors in my class for these as their names are based on database data. For example imagine we wanted to search for staff by their department, so our field name might be: people.sales people.customerservice Assume these departments would come from the DB and wouldn't be hard coded into code, and require a custom analyzer. In order to support specifying a custom analyzer for these records there would need to be a way of specifying a wildcard in the ScopeAnalyzer that would match "people.*". This is a feature I need, and something which may be needed in the future. I'm happy to develop a patch for it. The way I would propose to approach this is: 1) Make ScopedAnalyzer match wildcards, which could be done by holding a second map of analyzers, sorted by key longest first, and if an analyzer cannot be found directly for a given field wilcard matches can be checked. If a match is found it can be explicitly populated in the direct cache for immediate lookup. If there is a miss then the default analyzer can be inserted, saving further wildcard tests. Performance penalty would be minimal. 2) Configure ScopedAnalyzer with the wildcards. I can see two approaches to doing this: a) Create a new class level annotation @AnalyzerBindings that takes something like @AnalyzerBindings({ @AnalyzerBinding(pattern="person.department.*", impl=MyAnalyzer.class) }) Configure this from DocumentBuilder when the class is setup. b) Create a callback or other mechanism that allows custom bridges to specify which patterns they would like to match. I'd suggest a method like Map<String, Analyzer) getCustomAnalyzers () could be added to the Bridge interface (or another interface to avoid breaking changes) which could be called when the bridges are configured in DocumentBuilder. Any feedback on either approach is much appreciated. Cheers, Nick

16 years, 10 months

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hibernate-dev March 2008