Relationships

Ryx supports foreign-key relationships via #[relation(...)].

Defining a Relation

#[model]
struct Author {
    #[field(pk)]
    id: i64,
    name: String,
}

#[model]
#[relation(model = "Author", fk_column = "author_id", name = "author")]
struct Post {
    #[field(pk)]
    id: i64,
    title: String,
    author_id: i64,
    author: Option<Author>,
}

The #[relation] attribute has three parameters:

Parameter	Description
model	The related model type
fk_column	The foreign key column
name	The struct field holding the related model

The related field must be Option<RelatedModel> — it's populated by select_related.

select_related

Fetches related models in a single JOIN query, avoiding N+1:

let posts: Vec<Post> = Post::objects()
    .all()
    .select_related(&["author"])
    .all().await?;

for post in &posts {
    if let Some(author) = &post.author {
        println!("{} — by {}", post.title, author.name);
    }
}

Multiple relations:

Post::objects()
    .all()
    .select_related(&["author", "category"])
    .all().await?;

SQL Generated

SELECT "posts".*, "authors"."id" AS "author__id", "authors"."name" AS "author__name"
FROM "posts"
LEFT JOIN "authors" ON "posts"."author_id" = "authors"."id"

The result columns are aliased (author__id, author__name) and automatically decoded via FromRow::from_row_prefixed into the nested Option<Author>.

Next Steps

• Transactions — Atomic operations