About collection

forum_thread

Spring 4 setup

Can someone provide an example of setup ObjectDB embeded to be used with Spring4? Existing examples is like for Spring3 and I can't figure how to use ObjecDB in Spring tutorial: http://spring.io/guides/gs/accessing-data-jpa/   Thanx. #1 2014-09-20 10:26 Can someone provide an example of setup ObjectDB embeded to be used with Spring4? Existing examples is l ...

 
forum_thread

Enforce Second Level cache

In my application I have an entity with few transient Collection fields, these are constantly updateing very fast and access to those fields is needs to be fast too, thus I dont persist them (also this information is temporary and doesent need to be kept). I suppose that entity modified is the same that is cached in 2nd level cache. so that if i request that entity again I will get actually the same object with already ready state. Not sure about this but please leave your comment on this (is it really the same object kept in cache).... ... In my application I have an entity with few transient Collection fields, these are constantly updateing very fast and access to those ...

 
issue

Issue with full cross joins

hi, There seems to be an issue with full cross joins & maps. This query: ... JOIN has not been implemented and a map was handled as a collection of the first half of keys and values. Thank you for this ...

 
forum_thread

TreeSet and compareTo() issue

Hi I'm trying to use TreeSet but getting NPE on the compareTo() method when it does a find(): ... The dropdownValue's are accessed through a collection field in another class that uses eager fetch: @ ...

 
issue

JPQL support for Maps (JPA 2.0)

JPQL 2.0 introduces the ability define FROM variables for map keys and values. Currently ObjectDB supports FROM variables for collection elements and FROM variables for map keys and values are expected to be supported in future versions. ... values. Currently ObjectDB supports FROM variables for collection elements. FROM variables for map keys and values are expected to be ...

 
api-jpa

isCollection()

Is the attribute collection-valued (represents a Collection, Set, List, or Map).(Method of javax.persistence.metamodel.Attribute)

 
api-jdo

close()

Close this PersistenceManager so that no further requests may be made on it.(Method of javax.jdo.PersistenceManager)

 
api-jpa

OneToMany.cascade

(Optional) The operations that must be cascaded to the target of the association.(Annotation Element of javax.persistence.OneToMany)

 
forum_thread

can removing an entity throw an exception if the entity is in use?

Suppose you have an entity @Entity class A { ... } and other entities with references to A.   e.g. @Entity class B { A a; // explicit reference to A List<A> list; // list of A's Set<A> set; // set of A's Set untyped; // general collection that may include A's } Objectdb allows me to remove an instance of A, even if a managed B has some reference to that A. When I then find the B instance and try to reference the A, I get an EntityNotFoundException. ... ; // set of A's Set untyped ; // general collection that may include A's } Objectdb allows me to ...

 
api-jdo

addSubquery(sub, variableDeclaration, candidateCollectionExpression)

Add a subquery to this query.(Method of javax.jdo.Query)