How does orphanRemoval work with JPA and Hibernate
Introduction In this article, we are going to see how the JPA and Hibernate orphanRemoval mechanism allows us to trigger an entity child remove operation upon disassociating the child entity reference from the child collection on the parent side.
Java Map to JSON mapping with JPA and Hibernate
Introduction In this article, we are going to see how we can store Java Map entity attributes in JSON columns when using JPA, Hibernate, and the Hibernate Types project. While you can also persist Java Map entity attributes in PostgreSQL HStore columns, a JSON column type is a much more common option, especially since it works with other relational databases, like Oracle, SQL Server, or MySQL. As you already have seen, the Hibernate Types project allows you to map a JSON column type to a wide variety of JPA entity attributes, like… Read More
JPA and Hibernate Query setParameter – User Guide
Introduction In this article, I’m going to show you how the JPA Query setParameter method works for basic entity attributes, and how you can use it when dealing with custom Hibernate types. If you ever stumbled on the “column is of type jsonb but expression is of type bytea” PostgreSQL issue and didn’t know how to fix it, then you should definitely read this article.
How to get the SQL query from JPQL or JPA Criteria
Introduction In this article, I’m going to show you how you can get the auto-generated SQL query from a JPQL or JPA Criteria API entity query.
How to generate JPA entity identifier values using a database sequence
Introduction In this article, I’m going to show you how you can generate entity identifier values using a database sequence when using JPA and Hibernate. Using a database sequence is the most efficient Hibernate identifier generation strategy, as it allows you to take advantage of the automatic JDBC batching mechanism.
How to fetch a one-to-many DTO projection with JPA and Hibernate
Introduction In this article, I’m going to show you how you can fetch a one-to-many relationship as a DTO projection when using JPA and Hibernate. While entities make it very easy to fetch additional relationships, when it comes to DTO projections, you need to use a ResultTransformer to achieve this goal.
