Introduction In this article, I’m going to show you how you can return a Java Map result when executing a JPA query. I decided to write this article after answering a similar question on StackOverflow.
Introduction In this article, I’m going to present the best way to map a Java multidimensional array when using JPA and Hibernate. While one-dimensional array types have long been supported by the Hibernate Types open-source project, starting with the 2.9 release, you can now persist multidimensional array entity attributes with JPA and Hibernate.
Introduction In this article, I’m going to present the best way to prevent performance issues when using JPA and Hibernate. Many years ago, I used to work as a team leader, and, one day, the General Manager asked me to take a look at a project that was in big trouble. The application in question had been developed by a team of software developers for over 9 months, and the client had just tested in a production-like environment. The client got very upset when realizing that the application was barely crawling. For… Read More
Introduction In this article, I’m going to show you how to migrate from the legacy hilo sequence-based identifier optimizer to the pooled Hibernate strategy. I decided to write this article after having a discussion with Gerd Aschemann on Twitter about addressing the HHH-13783 Hibernate issue.
Introduction In this article, we are going to see how we can adjust a bulk update statement so that it takes optimistic locking into consideration. While Hibernate has been supporting versioned HQL queries for a very long time, it’s actually very easy to achieve this goal even with standard JPQL or JPA Criteria API.
Introduction If you’ve been using Hibernate for some time, there is a good chance you bumped into a MultipleBagFetchException issue: org.hibernate.loader.MultipleBagFetchException: cannot simultaneously fetch multiple bags In this article, we are going to see the reason Hibernate throws the MultipleBagFetchException as well as the best way to solve this issue.
Introduction In this article, we are going to see how we can load multiple entities by id at once when using JPA and Hibernate. Loading multiple entities by their identifier is a very common requirement when using JPA and Hibernate. Hence, we are going to see how we can optimize the underlying SQL query execution.
Introduction In this article, we are going to see how easy it is to map an SQL Server JSON column when using the Hibernate Types project. Not only that the hibernate-types project supports JSON column types for PostgreSQL and MySQL and Oracle, but, as you will see in this article, the JsonStringType works just fine when using Microsoft SQL Server.
Introduction In this article, we are going to see how to map the Oracle JSON column storage types when using JPA and Hibernate. My hibernate-types project has long been supporting JSON for PostgreSQL and MySQL. However, while developing my new and awesome SQL Master Class training, I realized that the current implementation does not handle Oracle JSON column types properly. Luckily, the fix was easy and starting with the 2.7.0 version you can now persist and fetch JSON attributes on Oracle using JPA and Hibernate.
Introduction In this article, we are going to see how we can write the best DTO projection JPQL query by omitting the package name when using JPA, Hibernate, and Spring. As I already explained, DTO projections are the most efficient way of fetching data when using JPA and Hibernate.