query_as! and query_file_as! macros ignore #[sqlx(default)]

[OriolMunoz]

Support for #[sqlx(default)] was implemented in #495, but it only affects usages of the non-macro sqlx::query_as(...).
However, this doesn't work for the macros query_as! and query_file_as!.

A test similar to the the following in macros.rs should reproduce the error:

#[derive(FromRow)]
struct Foo {
    id: i32,
    #[sqlx(default)]
    name: Option<String>,
}

#[sqlx_macros::test]
async fn test_query_as_default() -> anyhow::Result<()> {
    let mut conn = new::<Postgres>().await?;

    let foo = sqlx::query_as!(Foo, "SELECT id \"id!\" from (VALUES (1)) foos(id)",)
        .fetch_one(&mut conn)
        .await?;

    println!("{:?}", foo);

    Ok(())
}

error[E0063]: missing field `name` in initializer of `Foo`

Should/Could this be supported in sqlx, either through #[sqlx(default)] or some other mechanism? I had a glance at quote_query_as, columns_to_rust and expand_with_data, but I couldn't really tell 😞

[mehcode]

This is unfortunately not possible without some unstable rust features (and a rewrite of how the type-safe macros are implemented). See #514 to track from our side.