... 169Upgrading Drupal 6 themes to Drupal 7 171 Summary 172 Chapter 6: Drupal 7 Database Changes 173 What is DBTNG? 173 Background 174 Key concepts in DBTNG 174 Drivers 174 Connections 175 Statements 177 Queries ... introduced in Drupal 7. It looks at changes to the template les, JavaScript, CSS, and API. It also shows how to upgrade an existing Drupal 6 theme to Drupal 7. Chapter 6, Drupal 7 Database Changes, ... of the Drupal API. It introduces the reader to the DBTNG layer.Chapter 7, Drupal 7 for Developers, looks at the API in terms of upgrading your existing modules and site code to Drupal 7. It...