Most Java EE applications are stateless and there are good reasons for it. But not all user interactions can be implemented in that way. Sometimes you need to model a conversation that consists of multiple steps, like the typical shopping cart or complex update operations. Doing this with JPA 2.0 always felt a little bit…
Defining a static named query via the @NamedQuery annotation is the most common way in JPA. It has the main advantage that the persistence provider can compile and validate the query at start-up time. But you also have to define the query statically at compile time. OK, you can still define a dynamic query at runtime but how do you…
When you write a criteria query or create a dynamic entity graph, you need to reference the entity classes and their attributes. The quickest and easiest way is to provide the required names as Strings. But this has several drawbacks, e.g. you have to remember or look-up all the names of the entity attributes when you write the query….
Your entity classes map a database schema, which must be created before or during application startup. You can do this in various ways. You can run your own scripts, use tools like Flyway or Liquibase, or use the schema generation feature defined by the Jakarta Persistence specification (JPA). In this article, you will learn how…
Up to Version 2.1, JPA was missing real support for stored procedures. The only available option was to use a native query. This changed with JPA 2.1, when @NamedStoredProcedureQuery and StoredProcedureQuery were introduced as two of the new features. I wrote about @NamedStoredProcedureQuery and how to use it to define stored procedure calls in the…