Why are migration classes needed in Symfony/Doctrine?

Question

Doctrine ORM

Good afternoon, I read an article about migrating through Doctrine to Symfony
What are Doctrine-generated PHP classes for, by what principle are properties and methods generated in these classes, depending on the table structure?

Answer 1

Migrations are needed in order for the application to be responsible for its database.
You first change the code of the entity (entity), then do doctrine:migrations:diff, then it rolls up during the migration process.
It's in that order.