Skip to main content
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [List Home]
Re: [eclipselink-users] EclipseLink 1.1.0
What happens if you execute the query through a HistoricalSession? 
--Gordon

Magnus Heino wrote:

Hum. I do all that... I used to have triggers updating history tables, but I switch to have eclipselink maintain them now just in case...

Everything goes into my _HIST tables as expected. My query looks like this:

ReadObjectQuery query = new ReadObjectQuery(entity.getClass());
query.setSelectionCriteria(query.getExpressionBuilder().get("objectId").equal(entity.getObjectId()));
query.setAsOfClause(new AsOfClause(pastTime.getMillis()));
query.dontMaintainCache();
this.entityManager.getActiveSession().executeQuery(query);

SQL executed for this is not correct:

2009-03-19 18:24:36,515 [main] DEBUG [EL Fine]: ClientSession(28329183)--Connection(24758223)--SELECT ID, OBJECTVERSION, CONSTRUCTIONYEAR, HOUSENUMBER, EXTENSIONYEAR, VERSION, OBJECTID, OBJECTSTATUS, EXEMPTADDRESSING, EASEMENTBUILDING, MAINBUILDING, NONFREEHOLDPROPERTY, VERSIONVALIDFROM, VERSIONVALIDTO FROM BUILDING_HIST WHERE (((OBJECTID = ?) AND ((ROW_START <= ?) AND ((ROW_END IS NULL) OR (ROW_END > ?)))) AND ((ROW_START <= ?) AND ((ROW_END IS NULL) OR (ROW_END > ?))))
bind => [0e8d5e65-4ae9-443c-b70a-670b27892a5c, 2009-03-19 18:24:35.0, 2009-03-19 18:24:35.0, 2009-03-19 18:24:35.0, 2009-03-19 18:24:35.0] at se.lantmateriet.eclipselink.support.SLF4JSessionLogger.?(?:?)
2009-03-19 18:24:36,546 [main] DEBUG [EL Fine]: ClientSession(28329183)--Connection(24758223)--SELECT ID, VERSIONVALIDFROM, VERSIONVALIDTO, BUILDING_ID FROM REALPROPERTYREFERENCE WHERE (BUILDING_ID = ?)
bind => [1] at se.lantmateriet.eclipselink.support.SLF4JSessionLogger.?(?:?)
2009-03-19 18:24:36,593 [main] DEBUG [EL Fine]: ClientSession(28329183)--Connection(24758223)--SELECT ID, REALPROPERTYKEY, VERSIONVALIDFROM, VERSIONVALIDTO, LIESON_ID, AFFECTEDBY_ID, BELONGSTO_ID FROM REALPROPERTYKEY WHERE (LIESON_ID = ?)
bind => [3] at se.lantmateriet.eclipselink.support.SLF4JSessionLogger.?(?:?)
2009-03-19 18:24:36,625 [main] DEBUG [EL Fine]: ClientSession(28329183)--Connection(24758223)--SELECT ID, OBJECTVERSION, CONSTRUCTIONYEAR, HOUSENUMBER, EXTENSIONYEAR, VERSION, OBJECTID, OBJECTSTATUS, EXEMPTADDRESSING, EASEMENTBUILDING, MAINBUILDING, NONFREEHOLDPROPERTY, VERSIONVALIDFROM, VERSIONVALIDTO FROM BUILDING WHERE (ID = ?)
bind => [1] at se.lantmateriet.eclipselink.support.SLF4JSessionLogger.?(?:?)
2009-03-19 18:24:36,656 [main] DEBUG [EL Fine]: ClientSession(28329183)--Connection(24758223)--SELECT ID, VERSIONVALIDFROM, VERSIONVALIDTO, BUILDING_ID FROM REALPROPERTYREFERENCE WHERE (BUILDING_ID = ?)
bind => [1] at se.lantmateriet.eclipselink.support.SLF4JSessionLogger.?(?:?)
2009-03-19 18:24:36,687 [main] DEBUG [EL Fine]: ClientSession(28329183)--Connection(24758223)--SELECT ID, REALPROPERTYKEY, VERSIONVALIDFROM, VERSIONVALIDTO, LIESON_ID, AFFECTEDBY_ID, BELONGSTO_ID FROM REALPROPERTYKEY WHERE (BELONGSTO_ID = ?)
bind => [3] at se.lantmateriet.eclipselink.support.SLF4JSessionLogger.?(?:?)

It's first select goes for the right _HIST table, then all goes wrong...

Mappings are defined like this:

@PrivateOwned
    @OneToMany(cascade = CascadeType.ALL, mappedBy = "building")
    private Collection<Remark> remarks = new ArrayList<Remark>();

and on the other side:

@ManyToOne
    @JoinColumn(nullable = false)
    private Building building;

?

 /Magnus Heino


2009/3/19 Gordon Yorke <gordon.yorke@xxxxxxxxxx>
Our History support is at the Descriptor level.  Mappings like ManyToManyMapping and DirectCollectionMapping which perform direct writes to tables (like the join table) need special History support but the other mappings which do not manage tables themselves do not need any direct History support.

Our tests can be found in the package org.eclipse.persistence.testing.tests.history  the tests simply update an existing test model with history policies so that history is recorded and our standard tests plus some additional history specific tests are run against this model.

The EclipseLink User Guide has some information on how to configure EclipseLink to record and read in history. ( http://wiki.eclipse.org/Configuring_a_Descriptor_(ELUG)#Configuring_a_History_Policy ).  You will need to specify a DescriptorCustomizer to set the HistoryPolicy on your Entities.

Effectively a history policy configured on an Enitity tells EclipseLink how to record history and how to query for history.  To query against historical data you will need to use the native EclipseLink APIs and either acquire a HistoricalSession or set an AsOfClause on your query. 

See ( http://wiki.eclipse.org/Configuring_Historical_Sessions_(ELUG) ) the EclipseLink User Guide for details.

--Gordon


Magnus Heino wrote:

Could you please point me to a OneToOne and/or OneToMany example, test, or anything? I all can find are tests and references to HistoryPolicy in ManyToMany and DirectCollection.

ForeignReferenceMapping seems to have a prepareHistoricalQuery which seems to do just about nothing. CollectionMapping or OneToMany doesn't override it but ManyToManyMapping does. Or maybe I dont find the right details?

Thanks!

 /Magnus Heino


On Thu, Mar 19, 2009 at 3:49 PM, Gordon Yorke <gordon.yorke@xxxxxxxxxx> wrote:
Yes, History Policy is supported by OneToOne, OneToMany, DirectCollection, DirectToField (@Basic) and ManyToMany mappings.  If you need HistoryPolicy support you should be able to easily use a bi-directional OneToMany mapping.
As a paying Oracle customer you should speak with your support contact and your sales contact.  I have cc'd our product manager to let him know about your request.
As an EclipseLink community member file an enhancement request and vote for it.  Lobbing for the enhancement or even contributing the functional will expedite its inclusion.  You have already taken the first step by contacting us.
--Gordon


Magnus Heino wrote:


Historical Session support is a deferred requirement for Uni-direction One To Many Mapping.  It is mentioned in the document because it is functionality that we would like to add. 

Is it supported for any kind of OneToOne mapping? Reading org.eclipse.persistence.history.HistoryPolicy, I get the impression that's the case? :-P Makes this feature not so usable imho.

 
However, ss this functionality is not a must have for this feature it has been deferred from this release and has yet to be targeted for a future release.  If it is important to you file an enhancement request and vote for it.  Popularity of functionality helps us plan release targets.

As a paying Oracle customer, are there other ways to get this functionality in place?

Thanks,

/Magnus

 

--Gordon

Magnus Heino wrote:


Enhancements in JPA include:
 - a new 1:M mapping without that doesn't require a back pointer or a separate join table to hold the associations.

Reading this page http://wiki.eclipse.org/EclipseLink/Development/JPA2.0/uni-directional_onetomany_mapping I don't understand if HistoryPolicy is supported or not? Should these development pages be read as the way things probably will be implemented, or the way they were implemented?

 Implementation sequence#3 on that page says that Historical Sessions should be supported. A bit further down it reads that "History Policy is not supported with this mapping.". Without a history policy, no historical sessions afaik? Is the support for historical sessions there, if not, will it be there in the near future, or never?

/Magnus


_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users

_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users



_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users

_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users



_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users

Back to the top