Appendix D. Introduction to Doctrine

In this appendix, we provide overview of the Doctrine library, such as its architecture and components. Since in this book we concentrate mainly on Doctrine's Object Relational Mapper (ORM) component, reading this appendix may give you the bigger picture of other Doctrine capabilities.

• Doctrine and Database Management Systems
  • Relational Databases
    • SQL vs. DQL
  • NoSQL Databases
    • Document Databases
• Doctrine Architecture
  • Components Supporting Relational Databases
  • Components Supporting NoSQL Document Databases
• Summary