Fast Object Database for Java - with JPA/JDO support

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22

What algorithm in find()

I test the time cost for find(), obtain a linear complexity with the following codes:   int ... ();    Node p = em.find(Node.class, i/3);    if (null==p) System.out.printf("Node %d has no parent.%n ... a linear complexity, i.e. O(n). So what algorithm in find()? Can it improved to O(log(n)) complexity
21

Entity can be found by find() but not by query

Hello, we create an entity in transaction A, commit and close the transaction. After that in transaction B we try to find the entity in the DB. But we get always only a result with em.find(), with a query it is not always possible to get the entity, sometimes we get the entity
21

Query to find object from element of a contained collection

I have an OrderData class, containing an OrderItemData collection, i would like to find OrderData elements by OrderData.items.itemId. I cant get a proper query with MEMBER OF or IN. Does anyone have an idea on how i could formulate that as Typed or CriteriaBuilder query? Thanks. @Entity public
21

Cannot find objectdb-jee.jar releases in the ObjectDB maven repository

Hi, I can only find objectdb.jar releases in the ObjectDB maven repository. If objectdb-jee.jar releases are there, can you let me know where they are, otherwise would it be possible to include objectdb-jee.jar for the current and future maven releases ? Thanks Andrew andrewv Andrew Voumard
21

Find the error...JPA ENTITY HIBERNATE

Hey guys....i am searching for some days for the problem...Maybe one of you can find the error DATABASE SHEMA: https://www.file-upload.net/download-12530779/2017-06-0214_25_00-MySQLWorkbench.png.html Entities: package com.example.demo; import java.io.Serializable; import java.util.HashSet
21

Finding an object by its datetime

SearchBookingByTimeStamp() { Calendar btime = Calendar.getInstance(); btime.set(2012, 10, 11, 7, 30, 00); //This time is already inserted, trying to find it /* My Query */ TypedQuery query = em.createQuery( "SELECT b FROM Booking b WHERE b.btime = :btime
21

find repeated records by JPQL

Hi, I know a single command in MySQL can find repeated records: Select * from TTT t where id in (select id from TTT s group id having count(id)>1) I dont know how to do this using JPQL, but I use query from 430,000 records and put them into hashmap, finally it cost one hour and failed
21

Finding out the JPA provider

Do you have any preferred way of finding out whether ObjectDb is my EntityManager's JPA Provider? I know there are problems with using getDelegate ( http://weblogs.java.net/blog/ss141213/archive/2009/05/be_careful_whil.html ) but on the other hand unwrap is not very portable ( https://forums.oracle
20

finding post-persist pre-commit objects

finding post-persist pre-commit objects
20

How find out ObjectDB version at runtime (in a web app)

How find out ObjectDB version at runtime (in a web app)

Getting Started

ObjectDB is very easy to use. Follow the Getting Started Tutorial and the Quick Tour manual chapter and in minutes you may be able to write and run first Java programs against ObjectDB.

Prior knowledge or experience in database programming (SQL, JDBC, ORM, JPA, etc.) is not required, but some background in using the Java language is essential.

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