无法使用 SeaORM SELECT .all() - 特征 `ConnectionTrait` 未实现

Question

出现以下错误：

error[E0277]: the trait bound `Data<DatabaseConnection>: ConnectionTrait` is not satisfied
   --> src/main.rs:27:34
    |
27  |     let q = Articles::find().all(&data).await;
    |                              --- ^^^^^ the trait `ConnectionTrait` is not implemented for `Data<DatabaseConnection>`
    |                              |
    |                              required by a bound introduced by this call
    |
    = help: the following other types implement trait `ConnectionTrait`:
              DatabaseConnection
              DatabaseTransaction
note: required by a bound in `sea_orm::executor::select::<impl sea_orm::Select<E>>::all`
   --> /Users//.cargo/registry/src/git/sea-orm-0.10.6/src/executor/select.rs:267:12
    |
267 |         C: ConnectionTrait,
    |            ^^^^^^^^^^^^^^^ required by this bound in `sea_orm::executor::select::<impl sea_orm::Select<E>>::all`

main.rs：

async fn test(data: web::Data<DatabaseConnection>) -> HttpResponse {
    dbg!(&data);

    let q = Articles::find().all(&data).await;

    HttpResponse::Ok().json("test")
}

async fn get_connection() -> DatabaseConnection {
    Database::connect("postgres://...")
        .await
        .expect("Failed to connect to database!")
}

#[actix_web::main]
async fn main() -> Result<()> {
    let db = get_connection().await;

    HttpServer::new(move || {
        App::new()
            .service(web::resource("/").route(web::get().to(test)))
            .app_data(web::Data::new(db.clone()))
    })
    .bind(("127.0.0.1", 8888))?
    .run()
    .await?;

    Ok(())
}

Answer 1

您的错误显示“特征

ConnectionTrait

未针对

Data<DatabaseConnection>

实现”

这意味着 web::Data 没有实现 ConnectionTrait，因此您无法调用 Articles.find().all(&data)，因为数据的类型为 web::Data

您首先需要解开数据

async fn test(data: web::Data<DatabaseConnection>) -> HttpResponse {
    dbg!(&data);

    let conn = data.unwrap();

    let q = Articles::find().all(&conn).await;

    HttpResponse::Ok().json("test")
}