Introduction
============

The Doctrine **D**ata**B**ase **A**bstraction **L**ayer (DBAL) offers an
object-oriented API and a lot of additional, horizontal features
like database schema introspection and manipulation.

The fact that the Doctrine DBAL abstracts the access to the concrete
database away through the use of interfaces, makes it possible to implement
custom drivers that may use existing native or self-made APIs.
For example, the DBAL ships with a driver for Oracle databases that uses
the oci8 extension under the hood.

The following database vendors are currently supported:

- MySQL
- Oracle
- Microsoft SQL Server
- PostgreSQL
- SQLite

The Doctrine DBAL can be used independently of the
[Doctrine Object-Relational Mapper (ORM)](https://www.doctrine-project.org/projects/orm.html).
In order to use the DBAL all you need is
the class loader provided by [Composer](https://getcomposer.org/), to be able to autoload the classes:

.. code-block:: php

    <?php
    
    require_once 'vendor/autoload.php';

Now you are able to load classes that are in the
``/path/to/doctrine`` directory like
``/path/to/doctrine/Doctrine/DBAL/DriverManager.php`` which we will
use later in this documentation to configure our first Doctrine
DBAL connection.