Based on its javadoc, a java.util.List is supposed to represent an ordered collection of values. But that’s not necessarily the case if you use it as the type of a to-many association or an ElementCollection. As I explained before, Hibernate can handle a java.util.List as a Bag or a List. Only the List mapping persists the order…
After my talk about combining Flyway, Hibernate, and jOOQ at the JavaLand conference, one of the participants asked me how to add Flyway to an existing application that’s already deployed in production. This is a common question because database migrations get often ignored for new projects. And that’s understandable. You don’t need it for the…
One of the smaller changes in Hibernate 6 that can easily get overlooked, which Steve Ebersole presented in a recent Expert Session in the Persistence Hub, is the introduction of the MutationQuery and SelectionQuery interfaces. It allows the separation between queries that change data and the ones that select it from the database. Older Hibernate…
The Java Persistence Query Language (JPQL) is the most common way to query data from a database with JPA. It enables you to reuse your mapping definitions and is easier to use than SQL. But it supports only a small subset of the SQL standard, and it also provides no support for database-specific features. So…
Embeddables are simple Java objects. They provide an easy way to define and group a set of attributes that become part of your entity. Developers often use them to create reusable mapping information and handle them using the same piece of business code. Unfortunately, the JPA specification and Hibernate until version 6.0.0, required your embeddable…