Operations could take connection with unknown size

[billy1624]

PR Info

• Closes How do you seed data in migrations using ActiveModels? #522

• Dependencies:
  • Bump sea-orm version sea-schema#45

Fixes

• Methods that take in ConnectionTrait is implied to be with known sized, aka ConnectionTrait + Sized. But this assumption can be removed.

Breaking Changes

• Methods that take in ConnectionTrait, now take in ConnectionTrait + ?Sized

[tyt2y3]

I don't think it is an appropriate fix.
Should really try to fix it on SeaSchema side.
The root of the problem is the use of dyn vs use of enum for polymorphism, and SeaORM chose not to use dyn

[billy1624]

I think we should keep the SeaSchema migrator flexible and allow it to take anything that implemented ConnectionTrait. This way user can migrate with an ordinary connection or a transaction.

The SeaSchema Migration Manager: https://github.com/SeaQL/sea-schema/blob/db674ed28daff9bbfa3be51519f98ebaebf591b4/src/migration/manager.rs#L13

Also, in this PR, I relaxed the trait bound inside SeaORM, and I think the impact is minimum.

CC @tyt2y3

[Sytten]

It would be nice to decouple the schema connection from sea-orm. Someone using sea-query might want to use the schema migration (we were considering it yesterday to replace diesel migrations) without pulling the orm.
Maybe extracting the base trait to a core crate would do it. Should be fairly easy to then write bridges to any executor.

[tyt2y3]

I only think that SeaSchema should use generics and enums instead of dyn, unless there are clear reasons we can't

[tyt2y3]

It definitely is something we will look into - on breaking down SeaORM into types, driver & frontend crates.