How do you access Doctrine DBAL in a Symfony2 service class?

Question

I'm learning Symfony2 (and OOP) and want to create a service that's available throughout my app. This service takes a value foo, checks it against a database table, and returns a value bar.

I have a little class

namespace Acme\TestBundle\Toolbox;  class StringToolbox {     public function lookupSomething($foo)    {          $conn = $this->get('database_connection');         $sql = "SELECT bar FROM bar_list WHERE foo = :foo";         $stmt = $conn->prepare($sql);         $stmt->bindValue("foo", $foo);         $stmt->execute();           return $bar;     }   } 

My settings are:

services:     toolbox:        class:        Acme\TestBundle\Toolbox         arguments:   [@database_connection] 

But it throws an error saying that the get() method is undefined. I'm stuck-- how can I use DBAL in the service? Thanks!

Answer 1

First off you should add a constructor to your class and pass in the @doctrine.dbal.%connection_name%_connection service

namespace Acme\TestBundle\Toolbox; use Doctrine\DBAL\Connection;  class StringToolbox {     /**     *     * @var Connection     */     private $connection;      public function __construct(Connection $dbalConnection)  {         $this->connection = $dbalConnection;         }      public function lookupSomething($foo)     {      $sql = "SELECT bar FROM bar_list WHERE foo = :foo";     $stmt = $this->connection->prepare($sql);     $stmt->bindValue("foo", $foo);     $stmt->execute();       return $bar;     }   } 

Your service configuration should now look like this:

parameters:  my_service_connection: default  services:  toolbox:    class:        Acme\TestBundle\Toolbox\StringToolbox     arguments:   [@doctrine.dbal.%my_service_connection%_connection] 

What you are saying with this configuration is "make me a service named toolbox that will receive the doctrine.dbal.default_connection service as the first constructor argument"

There are other injection methods besides Constructor injection and you should read the http://symfony.com/doc/current/book/service_container.html documentation to get a grasp of all possibilities (Setter injection, Factory injection, etc) and to better understand how Dependency Injection works

Answer 2

@doctrine.dbal.connection not working, As Igor says, @doctrine.dbal.connection is an abstract, use @doctrine.dbal.default_connection if you only have one db connection, or @doctrine.dbal.%connection_name%_connection where the %connection_name% placeholder the name of the connection that you want to inject.

Your service configuration should now look like this:

services:  toolbox:    class:        Acme\TestBundle\Toolbox\StringToolbox     arguments:   [@doctrine.dbal.default_connection]