Introduction In this article, we are going to see how to order entity subclasses when executing a JPQL query with Hibernate.
Introduction As previously explained, the SINGLE_TABLE inheritance is the most efficient entity inheritance strategy. However, for JPQL query such as this one: Hibernate generates a SQL query which filters by the associated discriminator column (e.g. DTYPE by default): So, because we are filtering by the discriminator column, we might want to index it or include it to speed up queries. However, the default STRING DiscriminatorType expects a VARCHAR column that must hold the longest entity subclass name. For the Announcement class, we need at least 12 bytes to store the entity class… Read More