erreur cache with external parameters - database

Question

i would like to use external parameters to config my parameters.yml.
so i follow this tutorial :
http://symfony.com/doc/current/cookbook/configuration/external_parameters.html
in my parameters.yml i have put this :
parameters:
database_host: localhost
database_port: null
database_name: '%database.name%'
database_user: '%database.user%'
database_password: '%database.pass%'
mailer_transport: smtp
mailer_host: localhost
mailer_user: null
mailer_password: null
secret: ThisTokenIsNotSoSecretChangeIt
it works when i run my website with this parameters except when i clear the cache with command line.
i got this error :
[Symfony\Component\DependencyInjection\Exception\ParameterNotFoundException]
You have requested a non-existent parameter "database.name". Did you mean this: "database_name"?
Do you know the solution to resolve this problem.
thank you for your help

Answer 1

First create a php file and the logica, then import the php file to the config.yml and after comment the variables in parameters file. Have you tried to do something like this?
# parameters.php
$container->setParameter('database_name', $databaseName);
# app/config/config.yml
imports:
- { resource: parameters.php }
# app/config/parameters.yml
#database_name: '%database.name%'
#database_user: '%database.user%'