About FROM



Return the joins that have been made from this bound type.(Method of javax.persistence.criteria.From)



Interface used to interact with the persistence context.(Interface of JPA)



The CriteriaQuery interface defines functionality that is specific to top-level queries.(Interface of JPA)


Deleting JPA Entity Objects

Explains how to use JPA to delete (remove) entity objects from the database. Existing entity objects can be deleted from the database either explicitly by invoking the remove ... Explicit Remove In order to delete an object from the database it has to first be retrieved (no matter which way) and then ... ; The entity object is physically deleted from the database when the transaction is committed. Embedded objects that are ...


Issue with DISTINCT Select

It is getting more and more frustrating :( We've introduced distinct select instead of regular selection in our code (no changes else) and suddenly receive invalid identifiers in queries exceptions in various queries. Here's the stacktrace: ... query. Here it goes: SELECT DISTINCT $1 FROM com . quasado . foundation . contact . individual . ... causes more issues in explorer because the generated code from criteriaquery is NOT valid JPQL) -> you get the same issue. ...


Detached Entity Objects

Explains detached entity objects and how to work with detached objects in JPA, including merging them into an EntityManager.... ). Retrieval by navigation from detached objects is not supported, so only persistent fields that have ... EntityManager's method Remove the given entity from the persistence context, causing a managed entity to become detached. ...


[ODB1] Chapter 9 - ObjectDB Explorer

Explains how to view and manipulate database files in the database explorer. ... to start the Explorer. You can also start the Explorer from the command line. For instance, if the installation path of the ObjectDB ... persistent classes in the database. You can select a class from the list of classes at the top of this window and see all its persistent ...


query on calendar class

Hello!   I'm looking for help to build query on calendar class. I need to get objects where Calendar.DAY_OF_WEEK is FRIDAY or any other. My class: @Entity public class Cdr {     private static final long serialVersionUID = 1L;        @Id @GeneratedValue     private long serialID;     private String A;     @Temporal(TemporalType.TIMESTAMP) private Calendar start; I tested: ... Query query = em . createQuery ( "SELECT c FROM Cdr c where c.start.DAY_OF_WEEK = ?1" , Cdr . class ) ... javax.persistence.PersistenceException Navigation from 'java.util.Calendar' through 'DAY_OF_WEEK' is invalid ... by: com.objectdb.o.UserException: Navigation from 'java.util.Calendar' through 'DAY_OF_WEEK' is invalid at ...


JQL-Update Queries fails with activated L2-Cache

When using JQL-Update Queries it is basically not working without calling entityManager.clear() after a transaction commit. When the clear() method isn't called the entityManager will never return a container the updated Entities. Scenario 1: Disabled L2 Cache, updating elements using UPDATE-Query and fetching Entities afterwards from database. Expected result: Getting changed Entities from database - Actual result: No changes are visble. ... using UPDATE-Query and fetching Entities afterwards from database. Expected result: Getting changed Entities from database - Actual result: No changes are visble. Scenario 2 : ...


Database Schema Evolution

Explains how ObjectDB handles automatically schema changes.... is inconvertible to the new type (for instance a change from int to Date ) the fields are not considered as matching and the new ... following type conversions are supported: From any numeric type to any numeric type. In this context numeric types are: ...