Explain hibernate / database

[jnehring]

Please write a knowledge base article about the database connection with topics

• Maybe you can find an introduction to hibernate in the web, that explains what an Entity, Repository, Dao is?
• Explain how the database works and the differences between h2 file, h2 memory and mysql database. Point out that this is useful for unit
• Point to the database configuration. Point out that the database schema can be auto-generated by hibernate.
• Point to the restricted access article
• Explain the necessary packages for entities, repositories, daos (eu.freme.common.persistence...)