Unable to get binds when using Instrumentation and MultiConnection

[BlackDex]

Backend

PostgreSQL, MySQL, SQLite

Diesel version

2.3.1

Diesel Features

sqlite, chrono, r2d2, numeric

Operating System Version

Ubuntu 24.04

Third party libraries

No response

What do you want to do?

I want to implement a query logger via the usage of the Instrumentation functionality.
It works, in the sense that it shows me the query, but the binds are always empty.

I'm using the MultiConnection derive, not sure if that has any influence, because the migrations, when started on an empty database, do show the binds.

Compile time error

None

What code do you already have?

The main call to set it: diesel::connection::set_default_instrumentation(query_logger::simple_logger)

Just as test.

use diesel::connection::{Instrumentation, InstrumentationEvent};

pub fn simple_logger() -> Option<Box<dyn Instrumentation>> {
    Some(Box::new(|event: InstrumentationEvent<'_> | match event {
        InstrumentationEvent::StartEstablishConnection { url, .. } => {
            info!("Establishing connection: {url}")
        }
        InstrumentationEvent::StartQuery { query, .. } => info!("{query}"),
        _ => { info!("{event:#?}\n\n") }
    }))
}

Additional details

No response

Checklist

• I have already looked over the issue tracker and the discussion forum for similar possible closed issues.

[weiznich]

Thanks for reporting. I'm aware of that but I've not found the time to investigate why this is happening.

We likely miss to overwrite some method for the generated impls in #[derive(MultiConnection)]. This likely requires some digging through the expanded code or with an debugger to see where you get/not get that value from

[BlackDex]

Thx for the pointers.
I'll see when i have some time if i can figure it out and create a PR for it. Luckily it's more of an inconvenience, than a blocker.

[weiznich]

As I hit this as well on an internal project I decided to fix it now: #4795

[BlackDex]

Ah great! I didn't had any time yet to check my self. But nice that it will be solved.