The best way to fix the Hibernate MultipleBagFetchException
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.
The best way to fetch multiple entities by id using JPA and Hibernate
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.
How to map SQL Server JSON columns using JPA and Hibernate
Introduction In this article, we are going to see how easy it is to map an SQL Server JSON column when using the Hypersistence Utils project. The Hypersistence Utils project supports JSON column types for PostgreSQL and MySQL and Oracle, and, as you will see in this article, the JsonType works just fine with Microsoft SQL Server.
How to map Oracle JSON columns using JPA and Hibernate
Introduction In this article, we are going to see how to map the Oracle JSON column storage types when using JPA and Hibernate. The Hypersistence Utils project provides a generic JsonType that works with Oracle, SQL Server, PostgreSQL, and MySQL, and it can even use the columnDefinition attribute of the JPA @Column annotation to determine the underlying database column type.
How to write a compact DTO projection query with JPA
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.
How to map multiple JPA entities to one database table with Hibernate
Introduction In this article, we are going to see how we can map multiple JPA entities to one table with Hibernate. Using multiple entities can speed up both read and write operations. This question has been a recurring theme on StackOverflow, so I decided to explain the advantages of mapping multiple JPA entities to the same database table.
How to write JPA Criteria API queries using Codota
Introduction Writing JPA Criteria API queries is not very easy. The Codota IDE plugin can guide you on how to write such queries, which greatly simplifies the process. In this article, we are going to see how Codota works and how it can help you discover a given API.
Query timeout with JPA and Hibernate
Introduction In this article, we are going to see what is the best way to set up the query timeout interval with JPA and Hibernate. Setting the query timeout allows you to cancel slow-running queries that would, otherwise, put pressure on database resources.
A beginner’s guide to JPA and Hibernate query hints
Introduction In this article, we are going to see what JPA query hints are, and get to know all the query hints supported by Hibernate. Understanding the Hibernate query hints is very important when developing a non-trivial enterprise application since they allow you to customize the way queries are executed by Hibernate.
The best way to map an entity version property with JPA and Hibernate
Introduction In this article, we are going to see what is the best way to map the entity version property with JPA and Hibernate. Most often, we overlook the basic entity type mappings, focusing more on associations or querying options. However, basic types can also have a significant impact on application performance, especially if the type in question is used in many entity mappings.
