For the internet and eCommerce, database-driven applications are fundamental. This book provides the essential foundational knowledge and current techniques for using SQL and programming ORACLE databases with the free software ORACLE Express available online. The third edition has been updated and includes SQL developments that enable additional convenient processing methods. In particular, it addresses the ORACLE-specific programming language PL/SQL and the processing of XML documents. The success of the book is attributed to its strong application orientation and its convincing didactics, which consider not only the classical relational but also the object-relational perspective of database processing.