Symfony:动态更改数据库

假设我有3个数据库:

let's say I have 3 databases:

• prefix_db1
• prefix_db2
• prefix_db3
  

• prefix_db1
• prefix_db2
• prefix_db3
  

而且我想像这样的http://localhost/my-project/web/app_dev.php/db1/books从url动态连接到它们，所以我知道要从url连接到哪个数据库(在本例中为prefix_db1)
基本上，这个想法是准备一个将随每个 http请求触发的监听器，从url获取数据库名称，然后覆盖doctrin的参数，如下所示:
在 services.yml 中:

And I want to connect to them dynamically from the url like this http://localhost/my-project/web/app_dev.php/db1/books so I know which database to conenct to from the url (in this case prefix_db1)
And basically the idea was to prepare a listener that will be fired with each http request, get the database name from the url and then override doctrin's params, something like this:
Within services.yml:

dynamic_connection:
        class: AppBundle\service\DynamicDBConnector
        arguments:  ['@request_stack']
        calls:
            - [ setDoctrineConnection, ['@doctrine.dbal.default_connection'] ]
        tags:
            - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest }

我的听众:

<?php    
namespace AppBundle\service;

use Doctrine\DBAL\Connection;
use Symfony\Component\HttpFoundation\RequestStack;
use Exception;

class DynamicDBConnector
{
    /**
     * @var Connection
     */
    private $connection;

    /*
     * @var Request
     */
    private $request;


    public function __construct(RequestStack $requestStack)
    {
        $this->request = $requestStack->getCurrentRequest();

    }

    /**
     * Sets the DB Name prefix to use when selecting the database to connect to
     *
     * @param  Connection       $connection
     * @return DynamicDBConnector $this
     */
    public function setDoctrineConnection(Connection $connection)
    {
        $this->connection = $connection;
        return $this;
    }

    public function onKernelRequest()
    {
        if ($this->request->attributes->has('_company')) {

            $connection = $this->connection;
            $params     = $this->connection->getParams();

            $companyName = $this->request->get('_company');
            // I did the concatenation here because in paramaters.yml I just put the prefix (database_name: prefix_) so after the concatenation I get the whole database name "prefix_db1"
            $params['dbname'] = $params['dbname'] . $companyName;

            // Set up the parameters for the parent
            $connection->__construct(
                $params,
                $connection->getDriver(),
                $connection->getConfiguration(),
                $connection->getEventManager()
            );

            try {
                $connection->connect();
            } catch (Exception $e) {
                // log and handle exception
            }
        }

        return $this;
    }
}

现在这很好用了，我已经用一个简单的书籍列表对其进行了测试，每次更改url时，我都会得到与每个数据库相关的列表:

Now this worked very well I have tested it using a simple list of books and each time I change the url I get the list related to each database:

http://localhost/my-project/web/app_dev.php/db1/books // I get books of database prefix_db1

http://localhost/my-project/web/app_dev.php/db2/books // I get books of database prefix_db2

现在让我们来解决问题吧:):
现在的问题是，当我使用身份验证系统保护我的项目并尝试使用此URL http://localhost/my-project/web/app_dev.php/db1/login登录(当然每个数据库都有user表)时 我收到此异常:

Now let's get to the problem shall we :):
The problem now is that when I secure my project with authentication system and try to login (of course each database has user table) using this url http://localhost/my-project/web/app_dev.php/db1/login I get this exception :

An exception occured in driver: SQLSTATE[HY000] [1049] Base 'prefix_' unknown

您可以看到symfony尝试使用 parameters.yml 中声明的database_name登录用户，这意味着symfony的security_checker已在我的听众之前以及在覆盖教义的params.

我的问题:
有没有办法在其他任何HTTP请求侦听器之前触发我的侦听器?或者可能是另一种解决方案，以确保对数据库的任何请求都必须使用正确的数据库名称.
抱歉，很长的帖子.


来自symfony的官方文档:
https://symfony.com/doc/2.3/cookbook/event_dispatcher/event_listener.html

As you can see symfony tried to login the user using the database_name declared in parameters.yml which means that the security_checker of symfony has been fired before my listener and before overriding Doctrine's params.

My question:
Is there any way to fire my listener before any other http request listener ? or maybe an alternative solution to make sure that any request to database must be with the right database name.
Sorry for the long post.


From the official documentation of symfony:
https://symfony.com/doc/2.3/cookbook/event_dispatcher/event_listener.html

另一个可选的标签属性称为优先级，默认情况下 设置为0，并控制侦听器的执行顺序( 优先级最高，则监听器执行得越早).这是 当您需要确保在执行之前先执行一个侦听器时很有用 其他.内部Symfony侦听器的优先级通常 范围从-255到255，但您自己的听众可以使用任何正数或 负整数.

The other optional tag attribute is called priority, which defaults to 0 and it controls the order in which listeners are executed (the highest the priority, the earlier a listener is executed). This is useful when you need to guarantee that one listener is executed before another. The priorities of the internal Symfony listeners usually range from -255 to 255 but your own listeners can use any positive or negative integer.

我将侦听器的优先级设置为 10000 :

I set the priority of my listener to 10000:

tags:
    - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: 10000 }

但是问题仍然存在，仍然无法在symfony之前解雇我的听众！

But the problem persist, still can't fire my listener before symfony!