Add migration group ID to the SequelizeMeta table

[dpods]

Feature Description

Is your feature request related to a problem? Please describe.

Yes, migrations should be run as groups. If I have 3 new migrations that I created and I run db:migrate it will execute all 3 migrations.

The issue is if I need to rollback the migrations because all 3 migrations are not rolled back when I run db:migrate:undo. Only the last migration is rolled back. I need to run db:migrate:undo 3 times in order to completely roll back.

While frustrating, this is fine for local development. If this was a production environment where migrations are triggered automattically during the deploy sequence, this would be an issue. Now the rollback mechanism needs to have some kind of context around how many migrations last ran and how many times it needs to run db:migrate:undo

Describe the solution you'd like

Store a group_id number associated with each group of migrations that are run. That way, db:migrate:undo just needs to undo all of the migrations in the most recent migration group. This is how the Laravel framework solves this problem.

Now running db:migrate:undo would undo all 3 migrations rather than just the most recent one.

Why should this be in Sequelize

Because people rely on this library in production environments, and the need to rollback atomic changes to the database should work the same way as applying migrations.

Describe alternatives/workarounds you've considered

calling db:migrate:undo multiple times. Would need to build some sort of context to know how many migrations. previously ran.

Additional context

Feature Request Checklist

Is this feature dialect-specific?

• No. This issue is relevant to Sequelize as a whole.
• Yes. This issue only applies to the following dialect(s): XXX, YYY, ZZZ

Would you be willing to implement this feature by submitting a Pull Request?

• Yes, I have the time and I know how to start.
• Yes, I have the time but I don't know how to start, I would need guidance.
• No, I don't have the time, although I believe I could do it if I had the time...
• No, I don't have the time and I wouldn't even know how to start.

[ShaharHD]

Instead of having to run undo 3 times (per your example), you have the option of using a migration file per version.

You can extend that solution by having the actual migrations files in a sub-folder which corresponds to the version.
This will give you the "group" capability - but will require manual code on your end to handle up/down of the sub files.