Question

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.

Answer 1

Given an existing database with 1+ tables, running

./symfony doctrine:generate-migrations-db

will result in migration files being created for each table. Similarly, given a directory like /lib/model/doctrine filled with pre-existing model classes, running

./symfony doctrine:generate-migrations-models

will result in migraiton files being created for each model.

With tables in the database, with or without schema.yml contents, and no models in lib/model/doctrine, you just need to ensure you’re database.yml file has credentials to correctly connect to your database.

Once you figure out the problem with your migrations files not generating, what I would do is something like to get started with migrations.

1. Generate a fresh schema from your existing database with ./symfony doctrine:build-schema
2. Manually clean up the schema file, and re-establish your relations you’re already got existing in your model files (if any).
3. Reconfigure config/databases.yml to point to a new blank database
4. Build migrations with ./symfony doctrine:generate-migrations-diff. This will create migrations based on your schema file to bring your (blank) database up to date
5. Run ./symfony doctrine:migrate and watch for errors. Fix them by fixing your schema file. Delete the migrations created in Step 4. Flush your databse ./symfony doctrine:drop-db && ./symofny doctrine:build-db and go back to Step 4. Continue until you’re schema generates a clean set of migrations files that can run without error.
6. Rebuild your models with ./symfony doctrine:build --model --forms --filters

Now you have a clean schema.yml file, clean migrations that can bring a blank database up to date, and models that directly relate to your schema.yml file and database.

When you want to make a new change to your database, it’s now as simple as

1. Make the desired change in your schema.yml
2. Run ./symfony doctrine:generate-migrations-diff
3. Manually review the generated migrations
4. Run ./symfony doctrine:migrate to make sure the migrations run without error
5. Rebuild your model, forms, and filters ./symfony doctrine:build --model --forms --filters

Going through this process can be frustrating at times, but it’s something you only have to do once to create a really good based to build upon.