I wanted to use different database connections when accessing content. My main use case was to have a read-only user (e.g. reading from a read-replica) and a user with write permissions to do inserts.
This is something that both Symfony and Doctrine have supported for some time.
Doctrine config (doctrine.yaml)
doctrine:
dbal:
default_connection: default
connections:
default:
# configure these for your database server
url: '%env(resolve:DATABASE_URL_READ)%'
driver: 'pdo_mysql'
server_version: '5.7'
charset: utf8mb4
db_write:
# configure these for your database server
url: '%env(resolve:DATABASE_URL_WRITE)%'
driver: 'pdo_mysql'
server_version: '5.7'
charset: utf8mb4
orm:
auto_generate_proxy_classes: true
default_entity_manager: default
entity_managers:
default:
connection: default
naming_strategy: doctrine.orm.naming_strategy.underscore_number_aware
mappings:
App:
is_bundle: false
type: annotation
dir: '%kernel.project_dir%/src/Entity'
prefix: 'App\Entity'
alias: App
db_write:
connection: db_write
naming_strategy: doctrine.orm.naming_strategy.underscore_number_aware
mappings:
App:
is_bundle: false
type: annotation
dir: '%kernel.project_dir%/src/Entity'
prefix: 'App\Entity'
alias: App
This configuration is very similar to the one shown in the Symfony Docs. The main difference is that I want all my entities to be used by both connections.
The Repositories
I recently started creating my repositories like this (which is the recommended approach):
<?php
class EventRepository extends ServiceEntityRepository
{
public function __construct(ManagerRegistry $registry)
{
parent::__construct($registry, Event::class);
}
}
By using the ServiceEntityRepository it is auto-magically autowired in my dependencies.
Unfortunately, as I wanted to use the same entities with different entity managers, this approach would not work. (see: Issue with multiple entity managers)
The approach that did work, was to extend EntityRepository:
<?php
class EventRepository extends EntityRepository
{
}
Manage Dependencies
By no longer extending ServiceEntityRepository in the repository it means I now have to configure it manually.
Fortunately that is pretty straight-forward:
### Read DB Access
App\Event\Manager\Read\GetEvent:
class: App\Event\Manager\Read\GetEvent
arguments:
- "@=service('doctrine.orm.default_entity_manager').getRepository('App:Event')"
### Write DB Access
App\Event\Manager\Write\UpdateEvent:
class: App\Event\Manager\Write\UpdateEvent
arguments:
- "@=service('doctrine.orm.db_write_entity_manager').getRepository('App:Event')"
The only additional step I had to do to get this configuration to work, was to install the symfony/expression-language package.