sqlx: query_as! macros do not use FromRow

instead the query_as! macro’s directly build the target struct, while it might be nice not to have to derive FromRow for the struct, this also means that you can’t customize the behaviour with a custom FromRow implementation.

About this issue

Original URL
State: open
Created 4 years ago
Reactions: 17
Comments: 22 (3 by maintainers)

Most upvoted comments

Has any work been done on this? If not I’d be willing to try and help contribute this feature.

nrabulinski on Sep 19, 2022

It would be nice to have a note about this at the top of docs.rs/sqlx/0.5.5/sqlx/trait.FromRow.html . That’s where I started looking first when using sqlx(rename) didn’t work.

I’m sure adding more docs would be appreciated 😉

jplatte on Jun 18, 2021

I’ve just wrote my own implementation. Is it safe enough? And is it something you was looking for?

RoDmitry on Oct 3, 2023

Ah, thanks. const_panic is still a necessary feature for this, though, otherwise we can’t control the error message. There’s been some promising discussion on the tracking issue so I think I could push it through the stabilization process if I can find the time: https://github.com/rust-lang/rust/issues/51999

abonander on Jul 15, 2020

It can, but I’m not really happy about how the compiler currently handles const panics: https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=33e7700ac709e6581dcf478fb3c3b3b4

I proposed a format that would be more useful to us during the feature’s development, but it was brushed off: https://github.com/rust-lang/rust/issues/51999#issuecomment-651022782

We also can’t use Type::compatible() since trait methods can’t be invoked in const which would necessitate some more codegen hackery, like generating a #[doc(hidden)] pub const fn method in an inherent impl with #[derive(Type)].

abonander on Oct 3, 2023