In Criteria API, the javax.persistence.criteria.CriteriaUpdate interface defines functionality for performing bulk update operations.
Following method of CriteriaBuilder can be used to obtain CriteriaUpdate instance.
CriteriaUpdate<T> createCriteriaUpdate(Class<T> targetEntity)
Following is the CriteriaUpdate snippet:
public interface CriteriaUpdate<T> extends CommonAbstractCriteria {
Root<T> from(Class<T> entityClass);
Root<T> from(EntityType<T> entity);
Root<T> getRoot();
//Update the value of the specified attribute.
<Y, X extends Y> CriteriaUpdate<T> set( SingularAttribute<? super T, Y> attribute, X value);
<Y> CriteriaUpdate<T> set( SingularAttribute<? super T, Y> attribute, Expression<? extends Y> value);
<Y, X extends Y> CriteriaUpdate<T> set(Path<Y> attribute, X value);
<Y> CriteriaUpdate<T> set(Path<Y> attribute, Expression<? extends Y> value);
CriteriaUpdate<T> set(String attributeName, Object value);
CriteriaUpdate<T> where(Expression<Boolean> restriction);
CriteriaUpdate<T> where(Predicate... restrictions);
}
Quick Example
..................
CriteriaUpdate<Employee> criteriaUpdate = criteriaBuilder.createCriteriaUpdate(Employee.class);
Root<Employee> employeeRoot = criteriaUpdate.from(Employee.class);
criteriaUpdate.set(employeeRoot.get(Employee_.salary),
criteriaBuilder.sum(employeeRoot.get(Employee_.salary), 500d))
.where(criteriaBuilder.equal(employeeRoot.get(Employee_.DEPT), "IT"));
//the equivalent JPQL
//UPDATE Employee e SET e.salary = e.salary + 500 WHERE e.dept = 'IT'
entityManager.getTransaction().begin();
int i = entityManager.createQuery(criteriaUpdate).executeUpdate();
System.out.println("Entities updated: " + i);
entityManager.getTransaction().commit();
..................
Complete Example
JPA Entity
@Entity
public class Employee {
@Id
@GeneratedValue
private long id;
private String name;
private double salary;
private String dept;
.............
}
Using CriteriaUpdate
public class ExampleMain {
private static EntityManagerFactory entityManagerFactory =
Persistence.createEntityManagerFactory("example-unit");
public static void main(String[] args) {
try {
persistEmployees();
findAllEmployees();
updateITEmployeesSalaries();
findAllEmployees();
updateAllEmployeesSalaries();
findAllEmployees();
} finally {
entityManagerFactory.close();
}
}
private static void updateITEmployeesSalaries() {
System.out.println("-- increasing IT employees salaries by 500 --");
EntityManager entityManager = entityManagerFactory.createEntityManager();
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaUpdate<Employee> criteriaUpdate = criteriaBuilder.createCriteriaUpdate(Employee.class);
Root<Employee> employeeRoot = criteriaUpdate.from(Employee.class);
criteriaUpdate.set(employeeRoot.get(Employee_.salary),
criteriaBuilder.sum(employeeRoot.get(Employee_.salary), 500d))
.where(criteriaBuilder.equal(employeeRoot.get(Employee_.DEPT), "IT"));
//the equivalent JPQL
//UPDATE Employee e SET e.salary = e.salary + 500 WHERE e.dept = 'IT'
entityManager.getTransaction().begin();
int i = entityManager.createQuery(criteriaUpdate).executeUpdate();
System.out.println("Entities updated: " + i);
entityManager.getTransaction().commit();
entityManager.close();
}
private static void updateAllEmployeesSalaries() {
System.out.println("-- increasing all employees salaries by different percentage --");
EntityManager entityManager = entityManagerFactory.createEntityManager();
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaUpdate<Employee> criteriaUpdate = criteriaBuilder.createCriteriaUpdate(Employee.class);
Root<Employee> root = criteriaUpdate.from(Employee.class);
CriteriaBuilder.SimpleCase<String, Double> deptCase =
criteriaBuilder.selectCase(root.get(Employee_.DEPT));
Expression<Double> caseExpression =
deptCase.when("IT", criteriaBuilder.prod(root.get(Employee_.SALARY), 1.20))
.when("Admin", criteriaBuilder.prod(root.get(Employee_.SALARY), 1.15))
.otherwise(criteriaBuilder
.prod(root.get(Employee_.SALARY), 1.12));
criteriaUpdate.set(root.get(Employee_.salary), caseExpression);
//the equivalent JPQL
/*UPDATE Employee e SET e.salary =
CASE
WHEN e.dept = 'IT' THEN (e.salary * 1.20)
WHEN e.dept = 'Admin' THEN (e.salary * 1.15)
ELSE (e.salary * 1.12)
END*/
entityManager.getTransaction().begin();
int rowsUpdated = entityManager.createQuery(criteriaUpdate).executeUpdate();
System.out.println("entities Updated: " + rowsUpdated);
entityManager.getTransaction().commit();
entityManager.close();
}
public static void persistEmployees() {
Employee employee1 = Employee.create("Diana", 2000, "IT");
Employee employee2 = Employee.create("Rose", 3500, "Admin");
Employee employee3 = Employee.create("Denise", 2500, "Admin");
Employee employee4 = Employee.create("Mike", 4000, "IT");
Employee employee5 = Employee.create("Linda", 4500, "Sales");
EntityManager em = entityManagerFactory.createEntityManager();
em.getTransaction().begin();
em.persist(employee1);
em.persist(employee2);
em.persist(employee3);
em.persist(employee4);
em.persist(employee5);
em.getTransaction().commit();
em.close();
}
private static void findAllEmployees() {
EntityManager em = entityManagerFactory.createEntityManager();
System.out.println("-- All employees --");
Query query = em.createQuery(
"SELECT e FROM Employee e");
List<Employee> resultList = query.getResultList();
resultList.forEach(System.out::println);
em.close();
}
} -- All employees -- Employee{id=1, name='Diana', salary=2000.0, dept='IT'} Employee{id=2, name='Rose', salary=3500.0, dept='Admin'} Employee{id=3, name='Denise', salary=2500.0, dept='Admin'} Employee{id=4, name='Mike', salary=4000.0, dept='IT'} Employee{id=5, name='Linda', salary=4500.0, dept='Sales'} -- increasing IT employees salaries by 500 -- Entities updated: 2 -- All employees -- Employee{id=1, name='Diana', salary=2500.0, dept='IT'} Employee{id=2, name='Rose', salary=3500.0, dept='Admin'} Employee{id=3, name='Denise', salary=2500.0, dept='Admin'} Employee{id=4, name='Mike', salary=4500.0, dept='IT'} Employee{id=5, name='Linda', salary=4500.0, dept='Sales'} -- increasing all employees salaries by different percentage -- entities Updated: 5 -- All employees -- Employee{id=1, name='Diana', salary=3000.0, dept='IT'} Employee{id=2, name='Rose', salary=4024.9999999999995, dept='Admin'} Employee{id=3, name='Denise', salary=2875.0, dept='Admin'} Employee{id=4, name='Mike', salary=5400.0, dept='IT'} Employee{id=5, name='Linda', salary=5040.000000000001, dept='Sales'}
Example ProjectDependencies and Technologies Used: - h2 1.4.199: H2 Database Engine.
- hibernate-core 5.4.2.Final: Hibernate's core ORM functionality.
Implements javax.persistence:javax.persistence-api version 2.2 - hibernate-jpamodelgen 5.4.2.Final: Annotation Processor to generate JPA 2 static metamodel classes.
- JDK 1.8
- Maven 3.5.4
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