Following example shows how to use CriteriaBuilder.isMember() and CriteriaBuilder.isNotMember() methods.
These methods determine whether a value is an element of a collection.
package javax.persistence.criteria;
......
public interface CriteriaBuilder{
......
<E, C extends Collection<E>> Predicate isMember(Expression<E> elem, Expression<C> collection);
<E, C extends Collection<E>> Predicate isMember(E elem, Expression<C> collection);
<E, C extends Collection<E>> Predicate isNotMember(Expression<E> elem, Expression<C> collection);
<E, C extends Collection<E>> Predicate isNotMember(E elem, Expression<C> collection);
......
}
Quick Example
CriteriaQuery<Employee> criteriaQuery = criteriaBuilder.createQuery(Employee.class);
Root<Employee> employee = criteriaQuery.from(Employee.class);
criteriaQuery.select(employee)
.where(criteriaBuilder.isMember(criteriaBuilder.literal("222-222-222"),
employee.get(Employee_.phoneNumbers)));
TypedQuery<Employee> typedQuery = entityManager.createQuery(criteriaQuery);
List<Employee> list = typedQuery.getResultList();
In above example criteriaBuilder.literal() returns Expression. We can also use the other overloaded method of isMember() which takes element value instead of Expression:
......
criteriaQuery.select(employee)
.where(criteriaBuilder.isMember("222-222-222", employee.get(Employee_.phoneNumbers)));
......
Complete Example
Entities
@Entity
public class Employee {
@Id
@GeneratedValue
private long id;
private String name;
@ManyToMany(cascade = CascadeType.ALL)
private List<Task> tasks;
@ElementCollection
private List<String> phoneNumbers;
private String primaryPhoneNumber;
.............
}
@Entity
public class Task {
@Id
@GeneratedValue
private long id;
@Column(unique = true)
private String description;
private String supervisor;
.............
}
Main class using isMember() and isNotMember()
public class ExampleMain {
private static EntityManagerFactory entityManagerFactory =
Persistence.createEntityManagerFactory("example-unit");
public static void main(String[] args) {
try {
persistEmployees();
findEmployeeByPhoneNumber();
//with NOT and using parameter
findEmployeeByPhoneNumber2();
//Using isMember of value (phoneNumbers) from the same table (primaryPhoneNumber)
findEmployeeByMissingPhoneNumber();
//using another entity instance with MEMBER OF
findEmployeeByTaskDesc();
} finally {
entityManagerFactory.close();
}
}
private static void findEmployeeByPhoneNumber() {
System.out.println("-- Employees with phone number 222-222-222 --");
EntityManager entityManager = entityManagerFactory.createEntityManager();
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery<Employee> criteriaQuery = criteriaBuilder.createQuery(Employee.class);
Root<Employee> employee = criteriaQuery.from(Employee.class);
criteriaQuery.select(employee)
.where(criteriaBuilder.isMember(criteriaBuilder.literal("222-222-222"),
employee.get(Employee_.phoneNumbers)));
TypedQuery<Employee> typedQuery = entityManager.createQuery(criteriaQuery);
List<Employee> list = typedQuery.getResultList();
list.forEach(System.out::println);
entityManager.close();
}
private static void findEmployeeByPhoneNumber2() {
System.out.println("-- Employees with phone number NOT 222-222-222 --");
EntityManager entityManager = entityManagerFactory.createEntityManager();
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery<Employee> criteriaQuery = criteriaBuilder.createQuery(Employee.class);
Root<Employee> employee = criteriaQuery.from(Employee.class);
criteriaQuery.select(employee)
.where(criteriaBuilder.isNotMember("222-222-222",
employee.get(Employee_.phoneNumbers)));
TypedQuery<Employee> typedQuery = entityManager.createQuery(criteriaQuery);
List<Employee> list = typedQuery.getResultList();
list.forEach(System.out::println);
entityManager.close();
}
private static void findEmployeeByMissingPhoneNumber() {
System.out.println("-- Employees With PhoneNumbers List missing PrimaryPhoneNumber --");
EntityManager entityManager = entityManagerFactory.createEntityManager();
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery<Employee> criteriaQuery = criteriaBuilder.createQuery(Employee.class);
Root<Employee> employee = criteriaQuery.from(Employee.class);
criteriaQuery.select(employee)
.where(criteriaBuilder.isNotMember(employee.get(Employee_.primaryPhoneNumber),
employee.get(Employee_.phoneNumbers)));
TypedQuery<Employee> typedQuery = entityManager.createQuery(criteriaQuery);
List<Employee> list = typedQuery.getResultList();
list.forEach(System.out::println);
entityManager.close();
}
private static void findEmployeeByTaskDesc() {
System.out.println("-- Employees with task 'Designing' --");
EntityManager entityManager = entityManagerFactory.createEntityManager();
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
//find task by name first
CriteriaQuery<Task> criteriaQuery = criteriaBuilder.createQuery(Task.class);
Root<Task> task = criteriaQuery.from(Task.class);
criteriaQuery.select(task)
.where(criteriaBuilder.equal(task.get(Task_.description), "Designing"));
Task designingTask = entityManager.createQuery(criteriaQuery).getSingleResult();
//find employees now
CriteriaQuery<Employee> criteriaQuery2 = criteriaBuilder.createQuery(Employee.class);
Root<Employee> employee = criteriaQuery2.from(Employee.class);
criteriaQuery2.select(employee)
.where(criteriaBuilder.isMember(designingTask,
employee.get(Employee_.tasks)));
TypedQuery<Employee> typedQuery = entityManager.createQuery(criteriaQuery2);
List<Employee> list = typedQuery.getResultList();
list.forEach(System.out::println);
entityManager.close();
}
public static void persistEmployees() {
Task task1 = new Task("Coding", "Denise");
Task task2 = new Task("Refactoring", "Rose");
Task task3 = new Task("Designing", "Denise");
Task task4 = new Task("Documentation", null);
Employee employee1 = Employee.create("Diana", Arrays.asList("111-111-111", "222-222-222"),
"111-111-111", task1);
Employee employee2 = Employee.create("Mike", Arrays.asList("666-666-666", "444-444-444"),
"888-888-888", task2, task3);
Employee employee3 = Employee.create("Tim", Arrays.asList("555-555-555", "222-222-222"),
"222-222-222", task2);
Employee employee4 = Employee.create("Jack", Arrays.asList("333-333-333"),
"777-777-777", task4);
EntityManager em = entityManagerFactory.createEntityManager();
em.getTransaction().begin();
em.persist(employee1);
em.persist(employee2);
em.persist(employee3);
em.persist(employee4);
em.getTransaction().commit();
em.close();
System.out.println("-- Employee persisted --");
System.out.println(employee1);
System.out.println(employee2);
System.out.println(employee3);
System.out.println(employee4);
}
}-- Employee persisted --
Employee{id=1, name='Diana', tasks=[Task{id=2, description='Coding', supervisor='Denise'}], phoneNumbers=[111-111-111, 222-222-222], primaryPhoneNumber='111-111-111'}
Employee{id=3, name='Mike', tasks=[Task{id=4, description='Refactoring', supervisor='Rose'}, Task{id=5, description='Designing', supervisor='Denise'}], phoneNumbers=[666-666-666, 444-444-444], primaryPhoneNumber='888-888-888'}
Employee{id=6, name='Tim', tasks=[Task{id=4, description='Refactoring', supervisor='Rose'}], phoneNumbers=[555-555-555, 222-222-222], primaryPhoneNumber='222-222-222'}
Employee{id=7, name='Jack', tasks=[Task{id=8, description='Documentation', supervisor='null'}], phoneNumbers=[333-333-333], primaryPhoneNumber='777-777-777'}
-- Employees with phone number 222-222-222 --
Employee{id=1, name='Diana', tasks=[Task{id=2, description='Coding', supervisor='Denise'}], phoneNumbers=[111-111-111, 222-222-222], primaryPhoneNumber='111-111-111'}
Employee{id=6, name='Tim', tasks=[Task{id=4, description='Refactoring', supervisor='Rose'}], phoneNumbers=[555-555-555, 222-222-222], primaryPhoneNumber='222-222-222'}
-- Employees with phone number NOT 222-222-222 --
Employee{id=3, name='Mike', tasks=[Task{id=4, description='Refactoring', supervisor='Rose'}, Task{id=5, description='Designing', supervisor='Denise'}], phoneNumbers=[666-666-666, 444-444-444], primaryPhoneNumber='888-888-888'}
Employee{id=7, name='Jack', tasks=[Task{id=8, description='Documentation', supervisor='null'}], phoneNumbers=[333-333-333], primaryPhoneNumber='777-777-777'}
-- Employees With PhoneNumbers List missing PrimaryPhoneNumber --
Employee{id=3, name='Mike', tasks=[Task{id=4, description='Refactoring', supervisor='Rose'}, Task{id=5, description='Designing', supervisor='Denise'}], phoneNumbers=[666-666-666, 444-444-444], primaryPhoneNumber='888-888-888'}
Employee{id=7, name='Jack', tasks=[Task{id=8, description='Documentation', supervisor='null'}], phoneNumbers=[333-333-333], primaryPhoneNumber='777-777-777'}
-- Employees with task 'Designing' --
Employee{id=3, name='Mike', tasks=[Task{id=4, description='Refactoring', supervisor='Rose'}, Task{id=5, description='Designing', supervisor='Denise'}], phoneNumbers=[666-666-666, 444-444-444], primaryPhoneNumber='888-888-888'}
Example ProjectDependencies and Technologies Used: - h2 1.4.197: H2 Database Engine.
- hibernate-core 5.3.6.Final: Hibernate's core ORM functionality.
Implements javax.persistence:javax.persistence-api version 2.2 - hibernate-jpamodelgen 5.3.6.Final: Annotation Processor to generate JPA 2 static metamodel classes.
- JDK 1.8
- Maven 3.5.4
|
|
