rust-foundation-community-grant VS diesel_async

That's a topic where already some work exists. You might want to checkout my collection of bad error messages from such trait heavy crates for example. It's important to notice that most of these errors look complicated, but mostly have a quite simple cause. In some of these cases it's even possible to reword these error messages by removing most of the complicated looking type stuff to something much simpler which then is easier to understand.

As with everything in static type checking, the upfront costs seem high (deciphering type errors can be a bit daunting for both diesel, and to a certain extent dfdx), but I feel like (1) this will get better (especially with the work /u/weiznich is doing), and (2) history has shown the upfront costs are worth it (as evidenced by the takeover of typescript and typed Python).

This change is hopefully only the starting point to a number of future improvements. I've got a project grant as part of the rust foundation community grant program to work on improving the error messages for trait heavy crates like diesel. Hopefully this will result in other improvements as well. I track this work here. If you hit bad error messages with diesel or any other trait heavy crate, please fill an issue there.

axum does basically ]the trick as bevy](https://docs.rs/axum/latest/axum/handler/trait.Handler.html#impl-Handler%3C(T1%2C)%2C%20B%3E) to emulate variadics and someone already filed this https://github.com/weiznich/rust-foundation-community-grant/issues/2

So I want to use diesel_async in my web backend.

The already linked discussion from last time already contains a lot of information about this. Diesel itself does not provide async operations and that will likely remain that way for a foreseeable future. At least my preferred solution is to keep async support in a separate crate. A prototype for this is currently available here. Keep in mind that this is not released yet, so there might be bugs everywhere. I plan to cut a first release of this crate after the final release of diesel 2.0, which means hopefully soon. As for ETA's: I generally do not give any ETA's for releases, as this is currently a free time project for me.

So, diesel is an ORM that tries to take full advantage of rust's typing expressivity to allow for statically checked, and fast, queries. I absolutely loved it when trying it out the first time.

i don't see why you or anyone else would consider it too big of an issue that Diesel doesn't have async. For those who really want async diesel right now, the author already released diesel_async as a stop-gap solution, but even without that there's nothing wrong with using spawn_blocking. It feels worse than it really is to use blocking thread pools; until io_uring is a thing, there's no real getting around the necessity of threads being blocked for I/O and so adding async to the mix doesn't magically make things faster.

As for now there is an prototype available here. It's technically feature complete, but depends on a unpublished diesel version + has some remaining bugs with certain mysql versions. If that is fixed I will likely publish a first alpha version officially. That can take same time because that's a second large project that needs maintenance time beside diesel itself and that's quite a lot to do in my free time. You can support this work by sponsoring me on github

Async support for diesel currently lives in a separate repository as there are language level blocking issues for publishing a version of this crate where we could commit to a stable release at all. See the corresponding diesel issue for details.

https://github.com/weiznich/diesel_async tho'.

Weiznich (the maintainer of Diesel) has created an experimental async version of the diesel Connection and RunQueryDsl traits, which should help with ease-of-use for Diesel within async contexts. It is not yet published on crates, but you can find it here: https://github.com/weiznich/diesel_async