Opinionated JPA with Querydsl book finished!

I’m not sure I’ve ever had such a long pause in blogging – not that I blog that often, but still. I either didn’t want to blog about how not to do things (current project I’m working on), or made various notes for myself in GitHub markdown – or, slowly but surely, working on my… Continue reading Opinionated JPA with Querydsl book finished!

How I unknowingly deviated from JPA

In a post from January 2015 I wrote about possibility to use plain foreign key values instead of @ManyToOne and @OneToOne mappings in order to avoid eager fetch. It built on the JPA 2.1 as it needed ON clause not available before and on EclipseLink which is a reference implementation of the specification. To be… Continue reading How I unknowingly deviated from JPA

JPA – modularity denied

Here we are for another story about JPA (Java Persistence API) and its problems. But before we start splitting our persistence unit into multiple JARs, let’s see – or rather hear – how much it is denied. I can’t even think about this word normally anymore after I’ve heard the sound. 🙂 Second thing to… Continue reading JPA – modularity denied

EclipseLink joins without mapped attributes

EDIT April 2016: Originally I believed I described pure JPA 2.1 solution, much later I found it is merely an EclipseLink extension to the JPQL that is not supported in standard. OK, whoever knows it is possible, just stop reading right away (before my JPA rant starts). Note, that this post builds on JPA 2.1… Continue reading EclipseLink joins without mapped attributes

JPA – is it worth it? Horror stories with EclipseLink and Hibernate

One friend of mine brought Hibernate to our dev-team back in 2004 or so. But now he uses something much simpler and avoids ORM/JPA whenever possible. He can, because he is mostly master of his projects. I had to get more familiar with JPA on my path. There is always more and more to learn… Continue reading JPA – is it worth it? Horror stories with EclipseLink and Hibernate

JPA Pagination of entities with @OneToMany/@ManyToMany

Displaying paginated results of entities with their *-to-many sub-entities is a tricky thing and many people actually don’t even know about the problems. Let’s check what JPA does and what it does not for you. Besides standard JPA I’ll use Querydsl for queries – this effectively results in JPQL. Querydsl is type-safe and compared to… Continue reading JPA Pagination of entities with @OneToMany/@ManyToMany