About EntityManagerFactory

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How to define database structure and insert some initial objects from scratch

Hi from Spain! We're evaluating ObjectDB and we have some questions: - How can we create the initial database structure of our application? We know objectdb is all about objects and probably not need initial structure like tables, but how can we populate some "tables" with initial data from a script? In SQL world we have scripts like "insert into..." - Can we use main objectdb.jar library as jdbc driver for ETL software like Kettle? How about migrating data from another database system? ... a new database if it doesn't exist yet): EntityManagerFactory emf = Persistence . ...

 
forum_thread

java.sql.Timestamp with milliseconds

Using JPA with other providers java.util.Date will not provide support to store milliseconds, this can usually be overcome using (see here http://docs.oracle.com/javase/1.5.0/docs/api/java/sql/Timestamp.html) @Id @Column(name = "STMP") @Temporal(TemporalType.TIMESTAMP) private Timestamp timestamp; However with ObjectDB the milliseconds are not being stored, as shown this is an ID field and I am encountering duplicate ID errors trying to create multiple entries in the same second. ... [ ] args ) { EntityManagerFactory emf = Persistence . ...

 
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Query by array element

Hello, I have a class as follows: @Entity public class MyEntity {     boolean properties[]= new boolean[1024]; } I would like to query objects with feature '42': select me from MyEntity me where me.properties[42]=true Is it possible? Thank you! ... ] args ) {   EntityManagerFactory emf = Persistence . ...

 
issue

Can't open replicated database

I have a database running in server mode on port 6136 on server1 and server2. Each server has a replicated copy of the other servers database. I try to open the replicated on one database for a query (just read, no update) but it fails with the error below. The code I'm using is (user & password has been deliberately removed): ... & password has been deliberately removed): EntityManagerFactory emf = Persistence . createEntityManagerFactory ...

 
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Speed of queries that return many objects

Hi, I have a DB of 146MB - with 1_000_000 elements. Loading the contents (objectDB query in java) takes about 10sec. I am using a recent MacBook (SSD blabla - disk I/O speed is about 400MB/sec - according to blackMagicTest app for mac) - so I was expecting the query to take less than one sec (146/400 = 0.35sec.. + some overhead). I was wondering if this kind of speed is "normal", or if this is something I should investigate. Thanks EKK ... ( "user.dir" ) ; EntityManagerFactory emf = Persistence . createEntityManagerFactory ...

 
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Entity has be persistended,but query not fetched?

I create a new entity T newT and persistend it,then I create a query "select t from T t" to fetch all T entities.But  then the newT is not contain in the query result. Why? ... [ ] args ) { EntityManagerFactory emf = Persistence . ...

 
issue

Unexpected exception (Error 990) - Merge with no Transaction

I am frequently having an error when merging a detached object outside of a transaction. (Is this allowed? I am not trying to modify the object, just read data from it.) Here is a test case: ... , "xxxxxx" ) ; final EntityManagerFactory emf = Persistence . ...

 
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Items in list are doubled, when the entity class is not enhanced

Dear all, I have a problem with adding items (entities) into other entity list. When the classes are not enhanced, added items are doubled. Here is an example: ... [ ] args ) { EntityManagerFactory emf = Persistence . ...

 
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Accessing objects to make them available after EntityManager close?!

Hi, I would like to get all the instances of an entity object. So I wrote a function which returns a list of these instances. My problem is if I print out these instances before closing the em and returning the list, it works as I expected; if not, the function returns only one field correctly, another field is always Null. The details is as follows: ... getVifr_dicODB ( ) {   EntityManagerFactory emf = Persistence . ...

 
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Cascading merge() leading to "Attempt to persist a reference to a non managed instance" error

Dear Support Using Objectdb 2.3.4_02 I ran into an exception while performing some tests with a parent/child relationship and cascading merge() operations. The parent has an application defined id, while the child's id is generated, but I don't know if this is of concern. The following "test case" reproduces the error: ... public void go ( ) { EntityManagerFactory emf = Persistence . createEntityManagerFactory ...