Service Doctrine\DBAL\Driver\Connection is an instance of Doctrine\DBAL\Connection which does not implement Doctrine\DBAL\Driver\Connection

[chrif]

"doctrine/dbal": "^3.6",
"doctrine/doctrine-bundle": "^2.8",

In dbal.xml:
<service id="Doctrine\DBAL\Driver\Connection" alias="database_connection" public="false" />

This service enables autowiring on the Doctrine\DBAL\Driver\Connection interface but database_connection is an instance of Doctrine\DBAL\Connection which does not implement Doctrine\DBAL\Driver\Connection anymore in DBAL 3.x

So why keeping this definition? Is it only for backward compatibility? But if it makes autowiring fails it's not really backward compatible.

[ostrolucky]

Right below that there is a same alias for Doctrine\DBAL\Connection which should explain why nobody complained till now. Or do you have some scenario where you get autowiring error regarding this?

[chrif]

I'm upgrading an app from dbal 2 to 3. It had a custom service like this:

  doctrine.connection:
    class: Doctrine\DBAL\Driver\Connection
    factory: ['@doctrine.orm.entity_manager', getConnection]
    public: true

and developers were in the habit of injecting the Doctrine\DBAL\Driver\Connection interface with autowiring.

I replaced all usages of Doctrine\DBAL\Driver\Connection to Doctrine\DBAL\Connection and replaced the service with this definition:

  doctrine.connection:
    alias: 'doctrine.dbal.default_connection'
    public: true

Now developers need to lose the habit of autowiring Doctrine\DBAL\Driver\Connection which I thought would fail with a "no such service error". I was surprised to see instead an "interface not implemented" error, which is confusing.

I created a compiler pass to remove it.

[ostrolucky]

Since we don't support DBAL 2 anymore, indeed we should remove this alias.