What is the difference between em.find and em.createQuery

Question

em.find(Enity.classs, Id)

em.createQuery("SELECT e From Entity e WHERE e.Id=:id")

Are they equivalent? If not, How are they different?

Answer 1

The former might be faster because JPA provider does not have to parse the JPA query. But the resulting SQL should be exactly the same.

Also I think some providers might treat them differently with regards to caching - caching by key vs. query caching.

Finally the API is much more pleasant with find() - it either returns single entry or null. The latter either returns exactly one result (getSingleResult() - or throws) or returns a list (getResultList()).