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forum_thread

Type xxx is not found (error 301)

The error: Type User is not found (error 301) occurs when I query the db for a type before any instances of that type have been persisted, e.g.: return em.createQuery ("SELECT a FROM User a").getResultList (); What I was expecting was an empty list, not an error. Is there some enhancement that should be done beforehand?  ... observation is correct - this is the result of querying a class with no instances in the database. In standard JPA the solution ... In ObjectDB you can also introduce the new class before query execution by using: em. find ( User. ...

 
manual

JPA Named Queries

Explains how to define and how to run JPA named queries.... annotation is attached to exactly one entity class or mapped superclass - usually to the most relevant entity class. But since the scope of named queries is the entire persistence unit, ...

 
manual

JPA Metamodel API

Explains how to use the JPA Metamodel API to retrieve details on the types and attributes of the persistent object model.... methods can be used to retrieve a specific type by its Class instance: // Get a managed type (entity, embeddable or ... representing the entity, mapped superclass, or embeddable class. See JavaDoc Reference Page... ( MyClass. class ...

 
tutorial

Step 3: Define a Spring DAO Component

Explains how to define a JPA DAO component (bean) in a NetBeans Spring MVC JPA web application project.... MVC component: Open the [New Java Class] dialog box by right clicking the guest package node (in the [Projects] ... under Source Packages) and selecting New > Java Class... . Enter  GuestDao as the class name - ...

 
tutorial

Step 3: Define a Spring DAO Component

Explains how to define a JPA DAO component (bean) in an Eclipse Spring MVC JPA web application project.... MVC component: Open the [New Java Class] dialog box by right clicking the guest package node (in the [Package Explorer] window) and selecting  New > Class . The package name should be  guest . ...

 
api-jdo

setResultClass(cls)

Specify the type of object in which to return each element of the result of invoking execute or one of its siblings.(Method of javax.jdo.Query)

 
manual

[ODB1] Chapter 9 - ObjectDB Explorer

Explains how to view and manipulate database files in the database explorer. ... side of the Explorer desktop when a database is open. The "Class" window shows all the 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 ...

 
api-jpa

javax.persistence.metamodel.EntityType

Instances of the type EntityType represent entity types.(Interface of JPA)

 
forum_thread

Custom Classloader: Issues with the Enhancer Agent

In my use case I generate some classes dynamically and load them with a custom classloader. The classloader is very standard and does something like this (simplified): ... does something like this (simplified): public class MemoryClassLoader extends ClassLoader {   @ Override public Class< ? > findClass ( String name ) throws ...

 
api-jpa

javax.persistence.OneToOne

Defines a single-valued association to another entity that has one-to-one multiplicity.(Annotation of JPA)