The so-called “object-relation impedance mismatch” has long been discussed in engineering circles. Most attempts at a solution rely try to mask the issue by pulling logic into the application tier. Kostiantyn Cherniavskyi looks at these issues and shows how many of them can be solved with hybrid databases such as Starcounter.
ActiveJPA is a Java implementation of Martin Fowler’s Active Record pattern that wraps around JPA and provides useful abstractions to simplify data access. With ActiveJPA, models themselves act as a DAO and interact with the database without requiring additional code for the DAL. In this article the primary committer discusses ActiveJPA and provides plenty of usage examples.
The SQL language has been evolving steadily over the last two decades. At the same time, the verbosity caused by the JDBC API in Java client code and the lack of first class SQL support within the Java language have led to the introduction of ORMs such as Hibernate, which was later standardised into JPA and the Criteria API.If SQL and JPA are diverging, where will our data interaction patterns go?
The Android Developer’s Cookbook is a solid reference book for mobile app developers that can serve as an authoritative guide for sound programming practices. A nice addition to a dev's book shelf. 1
To refactor legacy code, the ideal is to have a suite of unit tests to prevent regressions. However it's not always that easy. This article describes a methodology to safely refactor legacy code. 7
Most ORM libraries make you write a new class for each item you want to keep in the database, extending this and that for no apparent reason. arrayDB looks at simplifying the whole process. 5
Yevhen Shchyholyev discusses some of the problems that the user may face in the process of developing an application with Entity Framework that interacts with Oracle, MySQL, PostgreSQL and SQLite.
Some see ORMs as an essential tool for simplifying data access while others claim it is needless complexity. Sam Saffron and Rob Conery have found a middle ground in what’s known as a Micro ORM. 5
OO7J is a Java version of the original OO7 benchmark (written in C++). This project includes benchmarking ORM tools. We recently interviewed OO7J's creator Pieter van Zyl about the project.
This article explores tuning techniques for Hibernate applications, focusing on poorly documented topics, such as inheritance mapping, second level cache and enhanced sequence identifier generators. 2
Scala and Spring are a promising match. Based on a concrete example, this article shows how the power of Scala combined with the proven and productive Spring framework can be unleashed. 5
Using the new DLR features in .NET 4 you can build a configuration-free ORM that uses the normal object-dot-property syntax without interfaces to define, classes to implement, or XML data mapping. 8