pdo_session_storage.rst

.. index::
   single: Session; Database Storage

How to use PdoSessionStorage to store Sessions in the Database

The default session storage of Symfony2 writes the session information to file(s). Most medium to large websites use a database to store the session values instead of files, because databases are easier to use and scale in a multi-webserver environment.

Symfony2 has a built-in solution for database session storage called :class:`Symfony\\Component\\HttpFoundation\\SessionStorage\\PdoSessionStorage`. To use it, you just need to change some parameters in config.yml (or the configuration format of your choice):

.. configuration-block::

    .. code-block:: yaml

        # app/config/config.yml
        framework:
            session:
                # ...
                storage_id:     session.storage.pdo

        parameters:
            pdo.db_options:
                db_table:    session
                db_id_col:   session_id
                db_data_col: session_value
                db_time_col: session_time

        services:
            pdo:
                class: PDO
                arguments:
                    dsn:      "mysql:dbname=mydatabase"
                    user:     myuser
                    password: mypassword

            session.storage.pdo:
                class:     Symfony\Component\HttpFoundation\SessionStorage\PdoSessionStorage
                arguments: [@pdo, %session.storage.options%, %pdo.db_options%]

    .. code-block:: xml

        <!-- app/config/config.xml -->
        <framework:config>
            <framework:session storage-id="session.storage.pdo" default-locale="en" lifetime="3600" auto-start="true"/>
        </framework:config>

        <parameters>
            <parameter key="pdo.db_options" type="collection">
                <parameter key="db_table">session</parameter>
                <parameter key="db_id_col">session_id</parameter>
                <parameter key="db_data_col">session_value</parameter>
                <parameter key="db_time_col">session_time</parameter>
            </parameter>
        </parameters>

        <services>
            <service id="pdo" class="PDO">
                <argument>mysql:dbname=mydatabase</argument>
                <argument>myuser</argument>
                <argument>mypassword</argument>
            </service>

            <service id="session.storage.pdo" class="Symfony\Component\HttpFoundation\SessionStorage\PdoSessionStorage">
                <argument type="service" id="pdo" />
                <argument>%session.storage.options%</argument>
                <argument>%pdo.db_options%</argument>
            </service>
        </services>

    .. code-block:: php

        // app/config/config.yml
        use Symfony\Component\DependencyInjection\Definition;
        use Symfony\Component\DependencyInjection\Reference;

        $container->loadFromExtension('framework', array(
            // ...
            'session' => array(
                // ...
                'storage_id' => 'session.storage.pdo',
            ),
        ));

        $container->setParameter('pdo.db_options', array(
            'db_table'      => 'session',
            'db_id_col'     => 'session_id',
            'db_data_col'   => 'session_value',
            'db_time_col'   => 'session_time',
        ));

        $pdoDefinition = new Definition('PDO', array(
            'mysql:dbname=mydatabase',
            'myuser',
            'mypassword',
        ));
        $container->setDefinition('pdo', $pdoDefinition);

        $storageDefinition = new Definition('Symfony\Component\HttpFoundation\SessionStorage\PdoSessionStorage', array(
            new Reference('pdo'),
            '%session.storage.options%',
            '%pdo.db_options%',
        ));
        $container->setDefinition('session.storage.pdo', $storageDefinition);

• db_table: The name of the session table in your database
• db_id_col: The name of the id column in your session table (VARCHAR(255) or larger)
• db_data_col: The name of the value column in your session table (TEXT or CLOB)
• db_time_col: The name of the time column in your session table (INTEGER)

Sharing your Database Connection Information

With the given configuration, the database connection settings are defined for the session storage connection only. This is OK when you use a separate database for the session data.

But if you'd like to store the session data in the same database as the rest of your project's data, you can use the connection settings from the parameter.ini by referencing the database-related parameters defined there:

.. configuration-block::

    .. code-block:: yaml

        pdo:
            class: PDO
            arguments:
                - "mysql:dbname=%database_name%"
                - %database_user%
                - %database_password%

    .. code-block:: xml

        <service id="pdo" class="PDO">
            <argument>mysql:dbname=%database_name%</argument>
            <argument>%database_user%</argument>
            <argument>%database_password%</argument>
        </service>

    .. code-block:: xml

        $pdoDefinition = new Definition('PDO', array(
            'mysql:dbname=%database_name%',
            '%database_user%',
            '%database_password%',
        ));

Example MySQL Statement

The SQL-Statement for creating the needed Database-Table could look like the following (MySQL):

CREATE TABLE `session` (
    `session_id` varchar(255) NOT NULL,
    `session_value` text NOT NULL,
    `session_time` int(11) NOT NULL,
    PRIMARY KEY (`session_id`),
    UNIQUE KEY `session_id_idx` (`session_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;