ORM - Object Relational Mapping:

The idea is to provide:
- pre-canned mapping between OO classes/fields and table/columns
- manually defined mappings
- provides object persistency without looking at the DB
Good:
- abstraction
- ease of debug
Bad:
- performance

Example: Hibernate

Example of Hibernate Mapping

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<hibernate-mapping>
<class name="de.laliluna.example.Honey" table="honey">
<id name="id" column="id" >
<generator class="increment"/>
</id>
<property name="name" column="fooname" />
<property name="taste" column="bartaste" />
</class>

</hibernate-mapping>
Example of Hibernate Usage (many details are hidden)
Honey honey = new Honey();
honey.setName("forest honey");
honey.setTaste("very sweet");
...
tx = session.beginTransaction();
session.save(honey);
tx.commit();
...
tx = session.beginTransaction();
session.update(honey);
tx.commit();
...
tx = session.beginTransaction();
List honeys = session.createQuery("select h from Honey as h").list();
tx.commit();

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Next we talk about DriadLINQ... it provides similar features but adds 
much more in particular:
- LINQ language integration
- Batch-oriented
- Cluster-oriented
- More than SQL

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