Nest 0 Cart
Nest Account
Popular Exams
All Categories...
Nest
Nest 0
Contact
Log In / Sign Up
Copyright 2024 © store. All rights reserved.
Home Oracle 1z0-898

Oracle 1z0-898 Exam Practice Questions (P. 3)

  • Full Access (63 questions)
  • Six months of Premium Access
  • Access to one million comments
  • Seamless ChatGPT Integration
  • Ability to download PDF files
  • Anki Flashcard files for revision
  • No Captcha & No AdSense
  • Advanced Exam Configuration
Get Contributor Access
Question #11
If an application uses an extended persistence context, which of the following is true?
  1. A
    The persistence context exists until all transactions invoked by the EntityManager complete.
  2. B
    The persistence context exists until all transactions invoked by the EntityManagar complete and the EntityManager.clear () method is invoked.
  3. C
    The persistence context exists until the EntityManager instance is closed.
  4. D
    The persistence context exists until the EntityManagerFactory instance is closed.

Correct Answer:
C
The extended persistence context exists from the point at which the entity manager has been created using EntityManagerFactory.createEntityManager until the entity manager is closed by means of EntityManager.close.
Reference: Identify correct and incorrect statements or examples about application-managed persistence contexts.

http://java.boot.by/scbcd5-guide/ch07s03.html

Question #12
An application uses an application-managed entity manager. Which of the following is NOT true?
  1. A
    The application may specify whether the scope of the persistence context is extended.
  2. B
    The application must use EntityManagerFactory instances to create entity managers.
  3. C
    Entity manager instances must be explicitly closed.
  4. D
    The application may need to call EntityManager. joinTransaction if a JTA aware entity manager is used.

Correct Answer:
D
When a JTA application-managed entity manager is used, if the entity manager is created outside the scope of the current JTA transaction, it is the responsibility of the application to associate the entity manager with the transaction (if desired) by calling EntityManager.joinTransaction.
Reference: Identify correct and incorrect statements or examples about application-managed persistence contexts.

http://java.boot.by/scbcd5-guide/ch07s03.html

Question #13
An application that uses container-managed transaction demarcation creates a query within an active transaction and receives a QueryTimeoutException. Which of those scenarios describes what happens to the active transaction?
  1. A
    The statement and the transaction continue.
  2. B
    The query is recreated within the current transaction.
  3. C
    The statement and the transaction are marked for rollback.
  4. D
    The statement is rolled back, but the transaction continues.

Correct Answer:
D
QueryTimeoutException is thrown by the persistence provider when a query times out and only the statement is rolled back. The current transaction, if one is active, will be not be marked for rollback.
Reference: javax.persistence, Class QueryTimeoutException
http://docs.jboss.org/hibernate/jpa/2.1/api/javax/persistence/QueryTimeoutException.html

Question #14
The developer has defined the following entity class office:
@Entity
public class Office {
@Id
private int id;
private String name;
@OneToMany
private List<Room> rooms;
}
Which of the following attributes will be in corresponding generated static metamodel class for the rooms field?
  1. A
    Public static volatile CollectionAttribute<Room> rooms;
  2. B
    Public static volatile ListAttribute<Room> rooms;
  3. C
    Public static volatile ListAttribute<Office, Room> rooms;
  4. D
    Public static volatile SingleAttribute<Room> rooms;

Correct Answer:
C
* Annotation Type OneToMany
Defines a many-valued association with one-to-many multiplicity.
* Interface ListAttribute<X,E>
Type Parameters:
X - The type the represented List belongs to
E - The element type of the represented List
Incorrect:
not A: A collection cannot reprecent a one to many relationship.
Reference: javax.persistence, Annotation Type OneToMany

Question #15
Given two entities with many-to-many bidirectional association between them:
@Entity public class Employee {
Collection projects;
// more code here
}
and
@Entity public class Project {
Set<Employee> emps;
// more code here
}
What set of annotations correctly defines the association?
  1. A
    @manyToMany on the projects field, @manyToMany (mappedBy= "projects") on the emps field
  2. B
    @manyToMany (mappedBy = emps) on the projects field, @manyToMany on the emps field
  3. C
    @manyToMany (targetEntity = project.class) on the projects field, @manyToMany (mappedBy = "projects") on the emps field
  4. D
    @manyToMany (targetEntity = project.class) on the projects field,

Correct Answer:
C
Every many to many relationship has obviously two sides: a Owning side and the Inverse side (which is... non-owning).
Here the Employee class is the owning side.
targetEntity: The entity class that is the target of the association. The dot (".") notation syntax must be used in the mappedBy element to indicate the relationship attribute within the embedded attribute.
This mappedBy element is mandatory and must be placed on the Inverse side of the relationship in case we are mapping a Bidirectional. Here Projects class is on the inverse side.
Note: @manyToMany defines a many-valued association with many-to-many multiplicity.
Every many-to-many association has two sides, the owning side and the non-owning, or inverse, side. The join table is specified on the owning side. If the association is bidirectional, either side may be designated as the owning side. If the relationship is bidirectional, the non-owning side must use the mappedBy element of the ManyToMany annotation to specify the relationship field or property of the owning side.
Reference: javax.persistence, Annotation Type ManyToMany
JPA 2 Tutorial Relationships Many To Many

Previous Questions Next Questions

All Pages