getting row data from sql::query_as

Question

Im trying to use sqlx to get data from a mysql db. I have the following:

#[derive(Debug, PartialEq, Eq, sqlx::FromRow)]
    struct Room {
        name: String
    }

    let mut stream = sqlx::query_as::<_, Room>(r#"SELECT name FROM rooms"#)
        .fetch_all(&db.pool).await;

    for row in stream {
        println!("{:?}",row);
    }

So in stream there is a vector and each index seems to hold the actual query results. So

stream[0] = [Room{name: "Room 1"}, Room{name: "Room 3"}, Room{name: "Room 2"}]

So in order to get at that data i have to loop through stream[0]. Is there a way to have that data on the value returned from the query without the explicit index?

Answer 1

Use Query::fetch() (this will return a stream of results, fetching the next one as needed) instead of Query::fetch_all() (this will return a vec of all results, fetching them all before hand), and then loop over the result stream.

Like so:

let mut stream = sqlx::query_as::<_, Room>(r#"SELECT name FROM rooms"#)
    .fetch(&db.pool);
stream.for_each(|room| println!("{:#?}", room));

Alternatively, you can use a while loop to print, but you may need to Pin your stream before calling next().

while let Some(room) = stream.next().await {
    println! ("{:#?}", room);
}