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Storing JPA Entity Objects

Explains how to use JPA to store (persist) entity objects in the database.... of entity objects that are reachable from that object by navigation through persistent reference fields is also stored in the database. ...

 
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Sorting problem

Hi, I was rewriting our DAO to support pagging in large dataset and I think I have found a problem with sorting. I send you a test case - sorry for using the same project as previous, but it was faster to write this test case. As usual, you can load data with DataLoader and then check problem with QueryData. There is a simple query with "order by" sentence: ... is considered as a string literal value rather than as a navigation expression), and because this constant expression is the same for ...

 
issue

OutOfMemoryError in a query with many variables

Just got this:   ... handle well queries with a lot of variables, and complex navigation (e.g.  ...

 
forum_thread

Optimization of Map Queries

hi! I am having loads and loads of occurrences of something like ((com.test.MyEntity) $1.map.get('com.test.MyEntity')).someProperty ... ((com.test.MyEntity) $1.map.get('com.test.MyEntity')).someOtherProperty .. ((com.test.MyEntity) $1.map.get('com.test.MyEntity')).someMoreProperties I need to use full qualified names for casting as well as for the map keys because same entity simple names may occur multiple times. Now I've got two questions: ... by ObjectDB users, but mainly for storage and retrieval or navigation, and rarely in queries. Actually support of querying maps in ...

 
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Error using query with MAX() function

I have a class that is persisting a Entity that holds remarks and a time. Then when I query for the latest remark I get a internal error when the remark is larger than 1966 chars. Here is a test class and entity that reproduces the problem on my system. #1 2011-04-24 04:51 I have a class that is persisting a Entity that holds remarks and a time. Then when I query for the lates ...

 
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Is 2 level cache in use?

Hi, Is there any way to check, if 2 level cache is in use? Right now I've done two things: 1. objectdb.conf with cache size is placed in WEB-INF directory of my web application. 2. persistence.xml was modified with: ... cache is mainly useful for retrieval by find and by navigation (and not in queries). You may try the following ...

 
issue

com.objectdb.o.InternalException NPE

[ObjectDB 2.2.9_10] Unexpected exception (Error 990)   Generated by Java HotSpot(TM) 64-Bit Server VM 1.7.0 (on Windows 7 6.1). Please report this error on http://www.objectdb.com/database/issue/new com.objectdb.o.InternalException: java.lang.NullPointerException: null java.lang.NullPointerException at com.objectdb.o.REG.S(REG.java:822) at com.objectdb.o.VAR.ap(VAR.java:731) at com.objectdb.o.XQI.Vf(XQI.java:69) at com.objectdb.o.TQI.Vf(TQI.java:67) at com.objectdb.o.TQI.Vf(TQI.java:67) at com.objectdb.o.TQI.Vf(TQI.java:67) at com.objectdb.o.MQI.Vf(MQI... The stack trace indicates navigation through a broken reference (probably a reference to a deleted ...

 
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JPQL IN Operator

How can I use the standard JPQL IN operator with ObjectDB? This JPQL query works fine with EclipseLink / postgres but throws an exception in objectDB: select distinct dv.creationtime from DataValue dv where dv.capabilityId.capabilityId ==> in <== :capabilities and dv.creationtime >= :earliest and dv.creationtime <= :latest order by dv.creationtime ASC [ObjectDB 2.2.9] javax.persistence.PersistenceException Unexpected query token 'in' (error 752) ... right side of a MEMBER OF operator (just collection navigation paths). I will check if a quick fix to support the in ...

 
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Object DB vs EclipseLink/TopLink: Unloaded relationships in detached entities

This topic is for those considering migrating from EclipseLink JPA or TopLink to ObjectDB JPA. ... The associated feature request is:  Navigation through lazy loading from Detached Objects   ...

 
manual

Strings in JPQL and Criteria Queries

Explains string expressions in JPQL queries, including LIKE, LOCATE, LOWER, UPPER, TRIM, CONCAT and SUBSTRING.... arguments. as  path expressions - in navigation to persistent string fields. as results of predefined ...