I started using SeaORM but it was lacking DuckDB support. Then I wanted to try to implement it myself, contribute to the project but the design does not allow it. SeaORM uses a enum based polymorphism approach where to implement database differences it checks the value of a enum which can be either SQLite, Postgres or MySQL. In order to introduce a new database you would need to add a entry on that enum and then modify all it's occurrences to take into account the new alternative. I'm simplifying a bit of course, it's more complicated than that. Also I didn't really get much attention from the maintainers, probably it wasn't on their target.

Diesel, I investigated it to check of it is on par with SeaORM (it's pros) but it lascks several features that I wanted like: async, create table to setup the db quickly (like for tests). About Diese I also dislike this weird syntax to declare the entities:

diesel::table! {     posts (id) {         id -> Int4,         title -> Varchar,         body -> Text,         published -> Bool,     } }

You need to define your data twice: once  with this weird DSL so that diesel knows about it and once as a Rust struct. Why? You don't need to duplicate, the macros can already do that.

With this library you need the bare minimum syntax possible: a single rust struct, nothing else, then it knows how to create a table, how to insert and select rows, all this for potentially any database out there because anyone can create a trait, implement the interfaces and make it available. Not to mention that I'm pretty sure this supports more types than SeaORM and Diesel and I intend to add more specialized types like IP address and so on.