Enum Error 

pub enum Error {
    MissingExtension,
    OverlappingExtractors,
    Database {
        error: Error,
    },
}

Possible errors when extracting Tx from a request.

Errors can occur at two points during the request lifecycle:

1. The Tx extractor might fail to obtain a connection from the pool and BEGIN a transaction. This could be due to:

   • Forgetting to add the middleware: Error::MissingExtension.
   • Calling the extractor multiple times in the same request: Error::OverlappingExtractors.
   • A problem communicating with the database: Error::Database.

2. The middleware Layer might fail to commit the transaction. This could be due to a problem communicating with the database, or else a logic error (e.g. unsatisfied deferred constraint): Error::Database.

axum requires that errors can be turned into responses. The Error type converts into a HTTP 500 response with the error message as the response body. This may be suitable for development or internal services but it’s generally not advisable to return internal error details to clients.

You can override the error types for both the Tx extractor and Layer:

• Override the Tx<DB, E> error type using the E generic type parameter. E must be convertible from Error (e.g. Error: Into<E>).

• Override the Layer error type using Config::layer_error. The layer error type must be convertible from sqlx::Error (e.g. sqlx::Error: Into<LayerError>).

In both cases, the error type must implement axum::response::IntoResponse.

use axum::{response::IntoResponse, routing::post};

enum MyError{
    Extractor(axum_sqlx_tx::Error),
    Layer(sqlx::Error),
}

impl From<axum_sqlx_tx::Error> for MyError {
    fn from(error: axum_sqlx_tx::Error) -> Self {
        Self::Extractor(error)
    }
}

impl From<sqlx::Error> for MyError {
    fn from(error: sqlx::Error) -> Self {
        Self::Layer(error)
    }
}

impl IntoResponse for MyError {
    fn into_response(self) -> axum::response::Response {
        // note that you would probably want to log the error as well
        (http::StatusCode::INTERNAL_SERVER_ERROR, "internal server error").into_response()
    }
}

// Override the `Tx` error type using the second generic type parameter
type Tx = axum_sqlx_tx::Tx<sqlx::Sqlite, MyError>;

let pool = sqlx::SqlitePool::connect("...").await.unwrap();

let (state, layer) = Tx::config(pool)
    // Override the `Layer` error type using the `Config` API
    .layer_error::<MyError>()
    .setup();

Variants

MissingExtension

Indicates that the Layer middleware was not installed.

OverlappingExtractors

Indicates that Tx was extracted multiple times in a single handler/middleware.

Database

A database error occurred when starting or committing the transaction.

Fields

error: Error

Trait Implementations

impl Debug for Error

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Error

fn fmt(&self, __formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for Error

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<Error> for Error

fn from(source: Error) -> Self

Converts to this type from the input type.

impl IntoResponse for Error

fn into_response(self) -> Response

Create a response.