How to map a JPA @ManyToOne relationship to a SQL query using the Hibernate @JoinFormula annotation

Introduction Someone asked me to answer the following StackOverflow question, and, because the question is very interesting from an SQL perspective, I decided to turn the answer it into a blog post. In this article, we are going to see how to map a JPA @ManyToOne association to the result of a SQL query using the Hibernate-specific @JoinFormula annotation.

How to map a @ManyToOne association using a non-Primary Key column with JPA and Hibernate

Introduction While answering questions on the Hibernate forum, I stumbled on the following question about using the @ManyToOne annotation when the Foreign Key column on the client side references a non-Primary Key column on the parent side. In this article, you are going to see how to use the @JoinColumn annotation in order to accommodate non-Primary Key many-to-one associations.

The best way to map a @OneToMany relationship with JPA and Hibernate

Introduction In a relational database system, a one-to-many association between links two tables based on a Foreign Key column so that the child table record references the Primary Key of the parent table row. As straightforward as it might be in a RDBMS, when it comes to JPA, the one-to-many database association can be represented either through a @ManyToOne or a @OneToMany association since the OOP association can be either unidirectional or bidirectional. The @ManyToOne annotation allows you to map the Foreign Key column in the child entity mapping so that the… Read More

Hypersistence Optimizer can automatically detect if you are using JPA and Hibernate properly