How to use Doctrine and what does it represent with ORM and PDO

Question

Doctrine:

Doctrine is an object relational mapper (ORM) for PHP 5.2.3+ that sits on top of a powerful database abstraction layer (DBAL). One of its key features is the option to write database queries in a proprietary object oriented SQL dialect called Doctrine Query Language (DQL), inspired by Hibernates HQL.

ORM:

Object relational mapping is a technique used in programming languages when dealing with databases for translating incompatible data types in relational databases. This essentially allows for us to have a "virtual object database,"

PDO:

???????????????

I cam to know that doctrine is an important lesson of PHP. I THINK it is used to close connections which are opened by clients automaticlly (dont know much about)

Can you give some examples which can explain what is its use and how it is used. And plz also explain above terms. I am not getting them technically...

Plz tell me in simple language so that i can learn it easily with examples which tell how to use it in my code.

Answer 1

Doctrine Documentation: Introduction

Covers these topics:

• Code Examples
• What is Doctrine?
• What is an ORM?
• What is the Problem?
• Minimum Requirements
• Basic Overview
• Doctrine Explained
• Key Concepts
• Further Reading
• Conclusion