Module toql::join::from_row

A join struct can contain either the full entity or just its key. This allows to load the full entity. For updates however you are not forced to set a full entity, if you only want to updating a foreign key.

Compare both

use toql::prelude::Join;

#[derive(Toql)]
struct User {
   #[toql(key)]
    id: u64,
    #[toql(join())]
    language: Join<Language>,
    #[toql(join())]
    country: Country
 }

For loading both language and country behave the same. The difference comes on updating: Let’s assume a web interface that can change both language and country. For language, the web client can only send back the key. It will deserialize into Join::Key. To change country however the client needs to send back a full valid country, otherwise the deserializer (serde) will fail. Likewise when programming Join is more ergonomic in update situations.