.fetch_all(&mut *db)
--------- ^^^^^^^^ the trait `sqlx::Executor<'_>` is not implemented for `&mut rocket_db_pools::sqlx::pool::PoolConnection<rocket_db_pools::sqlx::Postgres>

#[get("/tags")]
pub async fn fetch(
	mut db: Connection<Db>
) -> Result<Json<Vec<Tag>>, (Status, Json<ApiError>)> {
	sqlx::query_as!(Tag, "SELECT id, label, color FROM tag ORDER BY id")
		.fetch_all(&mut *db)
		.await
		.map(|tag| Json(tag))
		.map_err(|e| {
			ApiError::server_error(
				Status::InternalServerError, 
				&e.to_string()
			)
		})
}