How to count records in JPA using a NamedQuery

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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:

 @NamedQuery(name="Orders.countAll",
                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();

    }