About field

api-jpa

JPA Queries

Reference (JavaDoc) of all the JPA query types, including Query, TypedQuery, CriteriaBuilder, CriteriaQuery, Tuple, Root, Expression, Order, etc. Queries are represented in JPA by the Query and TypedQuery interfaces: javax.persistence.Query javax.persistence.TypedQuery The JPA Query API section (in chapter 4 of the ObjectDB manual) provides ...

 
forum_thread

TimeSeries and ObjectDB

Hi, I am using ObjectDB for storing TimeSeries (large ones) - when I get new points to add to the TimeSerie entity - I currently have to retrieve the whole timerserie since beginning of time, then add the new points, and then commit the whole timeserie again. I looked at Update queries - but they seem to be handling simple tasks - like multiply one field of the entity by a constant. More generally: 1- is ObjectDB suitable for large time series? 2/ If so - any example would be helpful - on how to organise the data. ... they seem to be handling simple tasks - like multiply one field of the entity by a constant. More generally: 1- is ...

 
forum_thread

Temporary disabling of indexes?

When populating a large database with objects that have indexed fields takes very much longer than populating the database with those objects if the index definitions are removed.  Is it possible to indicate in some way that for a particular use of the database indexes are to be ignored, and can be rebuilt later? #1 2016-06-29 18:30 When populating a large database with objects that have indexed fields takes very much longer than populating the ...

 
issue

@FetchGroup in JPA similar to JDO

I was checking what's new in different JPA implementation on the market and found quite interesting two features. First of those features is described in this ticket. It's similar to FetchGroup from JDO. It works like this. First you specify attributes to fetch from database: Feature Request Version: Priority: Normal Status: Active Replies: 0 Type:  Feature Request ...

 
api-jdo

Unique.members

Member (field and property) names that compose this unique constraint.(Annotation Element of javax.jdo.annotations.Unique)

 
tutorial

Step 2: Entity Class and Persistence Unit

To store objects in an ObjectDB database using JPA we need to define an entity class: Open the [New Java Class] dialog box, e.g. by right clicking the project node (in the [Package Explorer] window) and selecting  New > ...

 
api-jdo

javax.jdo.annotations.Element

Annotation for the element of a collection/array relation.(Annotation of JDO)

 
api-jpa

javax.persistence.MapKeyClass

Specifies the type of the map key for associations of type java.util.Map.(Annotation of JPA)

 
forum_thread

How does objectdb deal with conflicting schemas?

Suppose we have an objectdb network server with multiple clients connecting to it. Some clients have the latest object schema, matching that of the server. But some have an older schema, not using fields that have since been added. Will this work? #1 2012-03-15 21:48 Suppose we have an objectdb network server with multiple clients connecting to it. Some clients have the latest o ...

 
forum_thread

Bug with unique constraint exception not resulting in transaction roll back

I'm using ObjectDB 2.5.6_02 and running into a bug with a JDO @Unique constraint.  I'm using JPA in general. I have an EJB persisting two entities with @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW) declared on the EJB method.  The two entities have the same value for the field with the @Unique constraint. The unique constraint causes an exception as expected, but I would expect ObjectDB to roll back the transaction and not persist anything.  However, it is persisting both entities. ... method.  The two entities have the same value for the field with the @Unique constraint. The unique constraint causes an ...