rocket_db_pools sqlx migrations example?

[donpdonp]

I'm having a hard time trying to get sqlx migrations to run. Is there an example somewhere I can follow? The first challenge was getting a db connection from inside a fairing, but the two let db and let conn statements seem to be doing a good job of that.

#[launch]
 fn rocket() -> _ {
     rocket::build()
         .attach(AdHoc::on_liftoff("SQLX Migrate", |build| {
             Box::pin(async move {
                 let db = sql::AuthDb::fetch(&build).unwrap();
                 let mut conn = db.acquire().await.unwrap();
                 sqlx::migrate!("./sql").run(db);
             })
         }))

Calling migrate!().run generates this compile-time error:

error[E0277]: the trait bound `rocket_db_pools::sqlx::pool::PoolConnection<Postgres>: sqlx::Acquire<'_>` is not satisfied
   --> src/main.rs:53:45
    |
53  |                 sqlx::migrate!("./sql").run(conn);
    |                                         --- ^^^^ the trait `sqlx::Acquire<'_>` is not implemented for `rocket_db_pools::sqlx::pool::PoolConnection<Postgres>`
    |                                         |
    |                                         required by a bound introduced by this call
    |
    = help: the following other types implement trait `sqlx::Acquire<'c>`:
              <&'c mut sqlx::pool::PoolConnection<DB> as sqlx::Acquire<'c>>
              <&'t mut sqlx::Transaction<'c, DB> as sqlx::Acquire<'t>>
              <&'c mut AnyConnection as sqlx::Acquire<'c>>
              <&sqlx::Pool<DB> as sqlx::Acquire<'a>>
note: required by a bound in `Migrator::run`
   --> /home/donp/.cargo/registry/src/index.crates.io-6f17d22bba15001f/sqlx-core-0.7.1/src/migrate/migrator.rs:109:12
    |
107 |     pub async fn run<'a, A>(&self, migrator: A) -> Result<(), MigrateError>
    |                  --- required by a bound in this associated function
108 |     where
109 |         A: Acquire<'a>,
    |            ^^^^^^^^^^^ required by this bound in `Migrator::run`

[SergioBenitez]

Yes. https://github.com/SergioBenitez/Rocket/blob/26a3f00f82b6ddec2bbdb3ecb0c29d6ff0da7472/examples/databases/src/sqlx.rs

[NickUfer]

Can anybody explain why the example works but this code does not? I don't get it. It looks the same to me. And somehow I don't get it why people are actually using rust with this kind of constant torture.

Edit: Wtf... somehow the path created this trait problem. It does not make any sense to me. It doesn't like the migration in the folder, but why not is of course not explained because this language and everything surrounding it is actually made for bean counters.

My Code:

async fn run_migrations(rocket: Rocket<Build>) -> fairing::Result {
    if let Some(db) = Db::fetch(&rocket) {
        sqlx::migrate!("db/migrations")
            .run(&**db)
            .await?;
        Ok(rocket)
    } else {
        Err(rocket)
    }
}

Error:

error[E0277]: the trait bound `&rocket_db_pools::sqlx::Pool<rocket_db_pools::sqlx::Postgres>: sqlx::Acquire<'_>` is not satisfied
   --> src/main.rs:17:18
    |
17  |             .run(&**db)
    |              --- ^^^^^ the trait `sqlx::Acquire<'_>` is not implemented for `&rocket_db_pools::sqlx::Pool<rocket_db_pools::sqlx::Postgres>`
    |              |
    |              required by a bound introduced by this call
    |
    = help: the following other types implement trait `sqlx::Acquire<'c>`:
              <&'c mut sqlx::pool::PoolConnection<DB> as sqlx::Acquire<'c>>
              <&'t mut sqlx::Transaction<'c, DB> as sqlx::Acquire<'t>>
              <&'c mut AnyConnection as sqlx::Acquire<'c>>
              <&sqlx::Pool<DB> as sqlx::Acquire<'a>>
              <&'c mut sqlx::PgConnection as sqlx::Acquire<'c>>
note: required by a bound in `Migrator::run`
   --> /home/nick/.cargo/registry/src/index.crates.io-6f17d22bba15001f/sqlx-core-0.7.1/src/migrate/migrator.rs:109:12
    |
107 |     pub async fn run<'a, A>(&self, migrator: A) -> Result<(), MigrateError>
    |                  --- required by a bound in this associated function
108 |     where
109 |         A: Acquire<'a>,
    |            ^^^^^^^^^^^ required by this bound in `Migrator::run`

[SergioBenitez]

Likely because you're using sqlx 0.6 and the example is using 0.7.