Quick Refresher for ORM and Hibernate
I bumped into this post http://www.developersbook.com/hibernate/interview-questions/hibernate-interview-questions-faqs.php and found it very useful. However I tweaked a few questions and answers in a way that I understand better. Hence posting it here for future reference. 1.What is ORM ? ORM stands for object/relational mapping. ORM is the automated persistence of objects in a Java application to the tables in a relational database. 2.What does ORM consists of ? An ORM solution consists of the followig four pieces: API for performing basic CRUD operations API to express queries refering to classes Facilities to specify metadata Optimization facilities : dirty checking,lazy associations fetching 3.What are the ORM levels ? The ORM levels are: Pure relational (stored procedure.) Light objects mapping (JDBC) Medium object mapping Full object Mapping (composition,inheritance, polymorphism, persistence by reachab...