How to count records in JPA using a NamedQuery

Counting Records using a JPQL Query defined in a @NamedQuery

Here is a quick tip which shows how you can count your Database records using a NamedQuery in JPA. Here is the Named Query:

                query="SELECT COUNT(o) FROM Orders o")

Then, you can run the Named Query from any class which has access to the Entity Manager:

    public Number countAll() {
        return ((Number)entityManager.createNamedQuery("Orders.countAll").getSingleResult()).intValue();