What's the difference between generate-migrations-db and generate-migrations-models
===

What is the difference between

    symfony doctrine:generate-migrations-db

and

    symfony doctrine:generate-migrations-models

I can't notice any difference: I've tried with tables IN DB, NO schema.yml and NO models, both of them have no effect. No migrations generated.

I've tried with tables IN DB, GENERATED schema.yml and NO models, both of them have no effect. No migrations generated.

And lastly I've tried with tables IN DB, GENERATED schema.yml and GENERATED models, now both of them generate the same migrations classes :|.

Can't really understand the difference. Or at least, what is the best way to start using migrations considering all scenarious: having models, but no DB and having DB, but no models.

Thanks.