How to use auto incremented id's with MySQL when IDENTITY strategy is deprecated?

[ruudk]

We (and I think many older projects) heavily rely on auto incremented id's on MySQL. We use the IDENTITY strategy to automatically inject the last inserted ID into the entity.

Example:

#[Entity]
class MyEntity
{
    #[Id]
    #[Column(name: 'id', type: 'integer')]
    #[GeneratedValue(strategy: 'IDENTITY')]
    private $id;
}

I noticed that since a recent update, this is now marked as deprecated. What is the suggested migration path when on MySQL?

It didn't became clear from the issues:

• Deprecate reliance on sequence-emulated identity columns #9833
• Rework sequence-based identity generation #8850
• https://www.doctrine-project.org/projects/doctrine-orm/en/latest/reference/basic-mapping.html

[Fedik]

For auto-incremented id use of #[GeneratedValue] should be enough, by default it use strategy: AUTO., which will use IDENTITY for MySQL.
I am a bit misunderstood the question.

[ruudk]

@greg0ire would you happen to know the answer to this? It seems you created the deprecation in 3f84304. Does it mean that IDENTITY (AUTO) on MySQL is deprecated?

[ruudk]

AbstractMySQLPlatform does not overwrite usesSequenceEmulatedIdentityColumns, so therefore it delegates it to Doctrine\DBAL\Platforms\AbstractPlatform::usesSequenceEmulatedIdentityColumns that returns false and triggers the deprecation:
https://github.com/doctrine/dbal/blob/9a747d29e7e6b39509b8f1847e37a23a0163ea6a/src/Platforms/AbstractPlatform.php#L3943-L3953

Maybe the AbstractPlatform::usesSequenceEmulatedIdentityColumns should not trigger the deprecation?

[greg0ire]

If it returns false, you should not get a deprecation. And that's exactly what happens in ClassMetadataFactory, right?

[greg0ire]

Oh I get it now, you are getting a deprecation because usesSequenceEmulatedIdentityColumns is called. Would have been great to mention which deprecation you were having in your question, because as you can see, there are many of them.

[greg0ire]

So IDENTITY is not deprecated, what is really deprecated is calling usesSequenceEmulatedIdentityColumns. Do you confirm that's the deprecation you are getting?

[ruudk]

You're right, I was confused, sorry for that.

It's indeed the deprecation coming from AbstractPlatform::usesSequenceEmulatedIdentityColumns.

So the problem is that ClassMetadataFactory calls something that is deprecated, and should not call it.

[greg0ire]

Yes, and that's the case for ORM 3, but I don't see a way of avoiding that in ORM 2, unless maybe testing if the platform is an instance of this or that 😬