diesel VS rust-foundation-community-grant

7. Diesel

Both seem nice. However, both of them rely very heavily on prepared statements. Unfortunately, using prepared statements is a no-go when you use connection poolers like pgbouncer, or in my case AWS RDS proxy. A discussion in Diesel indicates that disel is not going to provide any support for disabling prepared stements (https://github.com/diesel-rs/diesel/discussions/3575), and a discussion on sqlx hints that disabling prepared statements is possible, but I haven't found any documentation or examples for it.

In addition we are experimenting with prebuild versions of diesel-cli that can be installed directly. We have a set of prebuilt binaries here. We are interested in feedback about how the provided binaries work on your platform.

First of all thanks for making this great tool. As it happens I currently toy around with using it for diesel-cli releases. See the WIP PR here. I think diesel-cli is a good example of a tool that depends on system libraries as it needs to link native database drivers, so this new release is welcome. Defining the dependencies seems to allow easily building things on x86_64-unknown-linux-gnu and x86_64-apple-darwin. It seems to pick up everything in the right way there.

I did look at mysql initially. Then I started checking other crates. Diesel is an Object Relation Model (ORM), I'm not yet keen on taking on the complication of learning ORM, I give this crate a pass in the meantime.

I would recommend people look at diesel from Rust for how nice it could be. https://diesel.rs/ Look at the complex queries example. So much more readable and easier to understand.

Most wanted missing features in diesel

There are two problems with using Rust for web servers:

1. The only production-ready Rust web servers require writing async request handlers. Async Rust is not fun.

2. The only good Postgres client library is async: https://crates.io/crates/sqlx

I'm trying to remedy the first problem with https://crates.io/crates/servlin .

Solving the second problem will be another project. I hope someone else does it. There is https://crates.io/crates/diesel but it has the same problem as async Rust: incomprehensible compiler errors.

Lemmy is written in Rust using Actix Web and Diesel.rs.

https://actix.rs/

https://diesel.rs/

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