In this chapter, we discussed querying in Hibernate. Hibernate provides three distinct ways to query the persistent objects: HQL, native SQL, and the Criteria API.
HQL is an SQL-like language that, unlike SQL (which works on raw data in the database), lets us express queries in an object-oriented form. Like SQL, HQL is not case-sensitive, but Java-related words, such as class and property names, should appear in the correct case.
The simplest form of HQL starts with a
from clause. A
where clause can be added to the end of a
from clause to restrict the query with constraints.
Hibernate lets us query persistent objects with native SQL. To execute a native SQL query, you can pass the query expression to the
createSQLQuery() method of