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Execute a SELECT query that returns a single untyped result.(Method of javax.persistence.Query)


Query Parameters in JPA

Explains how to use parameters (named parameters and ordinal parameters) in JPA queries.... with different parameter values to retrieve different results. Running the same query multiple times with different parameter values ... } The WHERE clause reduces the query results to Country objects whose name field value is equal to :name , ...


ObjectDB Object Database Features

ObjectDB provides a rich set of features, many of them as the result of supporting the JPA and JDO APIs. ObjectDB provides a rich set of features. Many features are implemented as part of ObjectDB's support of the JPA JPA Reference (JavaDoc) Java/JPA API Reference (based on the JPA 3 JavaDoc) See JavaDoc Reference Page... an ...


Memory leak with OutOfMemoryError exception

Hi, I'm new to using object databases. Currently I'm experience the following error: ... , symbol ) ;   List<DailyEntry> results = q. getResultList ( ) ;   em. close ( ) ;   return results ; } The method above is called from: for ...


Join performance in Objectdb

select count(e) from Meta e, ImageNet i, Page p where e.idImage=i.id and e.idPage=p.id; So simple a command cause me half an hour and is running now! Each table has about 160K records. What formula can predict the time for such counting? TIA ... to repeat this with the following test but could get your results. Can you change this test to demonstrate the execution time ...


JQL-Update Queries fails with activated L2-Cache

When using JQL-Update Queries it is basically not working without calling entityManager.clear() after a transaction commit. When the clear() method isn't called the entityManager will never return a container the updated Entities. Scenario 1: Disabled L2 Cache, updating elements using UPDATE-Query and fetching Entities afterwards from database. Expected result: Getting changed Entities from database - Actual result: No changes are visble. Bug Version: Priority: Critical Status: Closed Replies: 1 Type:  Bug ...


Retrieve data of all entity classes in a single query

I have in an objectdb file 10 Entity Classes with some data in each (Athlete, Trainer, Stadium etc) This is the code I use to retrieve all Managed Types and data for the Athlete class ... ; // I want to avoid this List<Athlete> results = query. getResultList ( ) ; for ( Athlete result : results ) { System. out . println ( ...


Slow searching with two indexes

I'm running queries on a large database (tens of millions of objects), and I'm running into a performance problem using two indexes.  An entity I'm querying has two indexed fields - one is the primary key (id) and so is different for each object, and the other is an object reference that only has a few tens of different values.   When I query by just the primary key, it's (of course) extremely fast, but when I also query using the other key, queries can take minutes.... id desc  With the query limited to (say) 10 results. Is there any obvious way to speed up this querying? ... ) .   [ Step 2 ] Order the results of step 1 by: desc ( any ( any ( this.id ) ...



Execute a SELECT query and return the query results as an untyped List.(Method of javax.persistence.Query)



Annotation for a named query.(Annotation of JDO)