In JPA 2, using a CriteriaQuery, how to count results

by

A query of type MyEntity is going to return MyEntity. You want a query for a Long.

CriteriaBuilder qb = entityManager.getCriteriaBuilder();
CriteriaQuery<Long> cq = qb.createQuery(Long.class);
cq.select(qb.count(cq.from(MyEntity.class)));
cq.where(/*your stuff*/);
return entityManager.createQuery(cq).getSingleResult();

Obviously you will want to build up your expression with whatever restrictions and groupings etc you skipped in the example.

More Related Contents:

  1. JPA Query selecting only specific columns without using Criteria Query?
  2. JPA CascadeType.ALL does not delete orphans
  3. How can I validate two or more fields in combination?
  4. Storing a Map using JPA
  5. How to properly express JPQL “join fetch” with “where” clause as JPA 2 CriteriaQuery?
  6. Hibernate – @ElementCollection – Strange delete/insert behavior
  7. JPA: unidirectional many-to-one and cascading delete
  8. JPA/Hibernate Static Metamodel Attributes not Populated — NullPointerException
  9. JPA Criteria API – How to add JOIN clause (as general sentence as possible)
  10. How do I properly cascade save a one-to-one, bidirectional relationship on primary key in Hibernate 3.6
  11. Silently ignored remove()
  12. JPA Criteria builder IN clause query
  13. How to define unidirectional OneToMany relationship in JPA
  14. Hibernate generates negative id values when using a sequence
  15. java.lang.IllegalStateException: Multiple representations of the same entity with @ManyToMany 3 entities
  16. Generate JPA 2 Entities from existing Database
  17. What is the purpose of AccessType.FIELD, AccessType.PROPERTY and @Access
  18. Rollback on every checked exception, whenever I say @Transactional
  19. Programmatically loading Entity classes with JPA 2.0?
  20. Hibernate triggering constraint violations using orphanRemoval
  21. JPA Criteria Tutorial [closed]
  22. Really dynamic JPA CriteriaBuilder
  23. Spring Data JPA: How can Query return Non- Entities Objects or List of Objects?
  24. SpringBoot doesn’t handle org.hibernate.exception.ConstraintViolationException
  25. Change Table Name of an Entity on runtime? [duplicate]
  26. JPA Select latest instance for each item
  27. Java EE Architecture – Are DAO’s still recommended when using an ORM like JPA 2?
  28. Why can outer Java classes access inner class private members?
  29. What is the difference between Unidirectional and Bidirectional JPA and Hibernate associations?
  30. Creating runnable JAR with Gradle

Leave a Comment