About collection

Collections in JPQL and Criteria Queries

Shows how collections and maps can be used in JPQL queries.... as path expressions - in navigation to persistent collection fields. This page covers the following topics: ... [OF] [NOT] IN Criteria Query Collection Expressions IS [NOT] EMPTY The IS ...

JPA Query Expressions (JPQL / Criteria)

Describes JPA query (JPQL / Criteria API) expressions (literals, operators and functions).... IS [NOT] NULL, [NOT] BETWEEN, including Collection operators: [NOT] IN, IS [NOT] EMPTY, [NOT] MEMBER [OF] ... See JavaDoc Reference Page... ). Collection expressions ( isEmpty isEmpty(collection) ...

JPA Persistable Types

Explains how JPA manages types, including entity classes, embeddable classes, primitive types, wrappers, string, date, enum, collections and maps.... multi value types are persistable: Collection types from package java.util : ArrayList , Vector , Stack ... ) and non generic (e.g. ArrayList ) collection and map types are supported, as long as their values (i.e. elements ... of persistable types. In addition to the collection and map classes that are fully supported by ObjectDB, any other ...

getObjectsById(oids, validate)

Return the objects with the given oids.(Method of javax.jdo.PersistenceManager)

[ODB1] Chapter 7 - JDOQL Queries

Explains how to use JDOQL, the Java/JDO Query Language.... has the following three components: A candidate collection containing persistent objects (usually an Extent ) A ... The query result is a subset of objects from the candidate collection that contains only the instances of the candidate class satisfying ...

isEmpty(collection)

Create a predicate that tests whether a collection is empty.(Method of javax.persistence.criteria.CriteriaBuilder)

isNotEmpty(collection)

Create a predicate that tests whether a collection is not empty.(Method of javax.persistence.criteria.CriteriaBuilder)

collection of embedded objects

1. In general, are there any restrictions of the use of @Embedded objects in collections, compared to @Entity? 2. If you have a large nested collection of @Embedded objects, and you remove the parent @Entity, does the remove cascade through the whole collection? 3. Is searching through collections of @Embedded objects more expensive (time) than searching through collections of @Entity? ... to @Entity ? 2. If you have a large nested collection of @Embedded objects, and you remove the parent @Entity , does the remove cascade through the whole collection? 3. Is searching through collections of @Embedded ...

size(collection)

Create an expression that tests the size of a collection.(Method of javax.persistence.criteria.CriteriaBuilder)

Custom collection types

Hi In our project in few places there are used collections from emf framework eg EcoreEMap http://download.eclipse.org/modeling/emf/emf/javadoc/2.5.0/org/eclipse/emf/ecore/util/EcoreEMap.html This is strange map for me, it implements List interface but does not implement Map interface, nevertheless it causes some questions. ... I checked that i can easily change the type of collection between eg Vector, ArrayList, HashSet and all works fine, moreover ... which are not in java.util package? if this collection type will be used in first app release to allow data to be imported ...