问题
What are the differences between a query, a native query, a named query and a typed query? Does the 'alone-standing' query even exist, or is it just an abbreviation? In my mind, a native Query is a query written in simple sql, whereas a named query relates to entities (hibernate-mapping). Can someone explain this briefly?
回答1:
Query
Query refers to JPQL/HQL query with syntax similar to SQL generally used to execute DML statements(CRUD operations).
In JPA, you can create a query using entityManager.createQuery(). You can look into API for more detail.
In Hibernate, you use session.createQuery()"
NativeQuery
Native query refers to actual sql queries (referring to actual database objects). These queries are the sql statements which can be directly executed in database using a database client.
JPA : entityManager.createNativeQuery()
Hibernate (Non-JPA implementation): session.createSQLQuery()
NamedQuery
Similar to how the constant is defined. NamedQuery is the way you define your query by giving it a name. You could define this in mapping file in hibernate or also using annotations at entity level.
TypedQuery
TypedQuery gives you an option to mention the type of entity when you create a query and therefore any operation thereafter does not need an explicit cast to the intended type. Whereas the normal Query API does not return the exact type of Object you expect and you need to cast.
来源：https://stackoverflow.com/questions/33236664/difference-between-query-native-query-named-query-and-typed-query