You don't have to write this by hand! Entity files can be generated from an existing database with sea-orm-cli.

use sea_orm::entity::prelude::*;

#[sea_orm::model]
#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
#[sea_orm(table_name = "user")]
pub struct Model {
    #[sea_orm(primary_key)]
    pub id: i32,
    pub name: String,
    #[sea_orm(unique)]
    pub email: String,
    #[sea_orm(has_one)]
    pub profile: HasOne<super::profile::Entity>,
    #[sea_orm(has_many)]
    pub posts: HasMany<super::post::Entity>,
}

impl ActiveModelBehavior for ActiveModel {}

The Entity Loader intelligently uses join for 1-1 and data loader for 1-N relations, eliminating the N+1 problem even when performing nested queries.

// join paths:
// user -> profile
// user -> post
//         post -> post_tag -> tag
let smart_user = user::Entity::load()
    .filter_by_id(42) // shorthand for .filter(user::COLUMN.id.eq(42))
    .with(profile::Entity) // 1-1 uses join
    .with((post::Entity, tag::Entity)) // 1-N uses data loader
    .one(db)
    .await?
    .unwrap();

smart_user
    == user::ModelEx {
        id: 42,
        name: "Bob".into(),
        email: "bob@sea-ql.org".into(),
        profile: HasOne::Loaded(profile::ModelEx {
            picture: "image.jpg".into(),
        }.into()),
        posts: HasMany::Loaded(vec![post::ModelEx {
            title: "Nice weather".into(),
            tags: HasMany::Loaded(vec![tag::ModelEx {
                tag: "sunny".into(),
            }]),
        }]),
    };

Persist an entire object graph: user, profile (1-1), posts (1-N), and tags (M-N) in a single operation using a fluent builder API. SeaORM automatically determines the dependencies and inserts or deletes objects in the correct order.

let user = user::ActiveModel::builder()
    .set_name("Bob")
    .set_email("bob@sea-ql.org")
    .set_profile(profile::ActiveModel::builder().set_picture("image.jpg"))
    .add_post(
        post::ActiveModel::builder()
            .set_title("Nice weather")
            .add_tag(tag::ActiveModel::builder().set_tag("sunny")),
    )
    .save(db)
    .await?;

SeaORM 2.0 supports a first-class Entity First Workflow: simply define new entities or add columns to existing ones, and SeaORM will automatically detect the changes and create the new tables, columns, unique keys, and foreign keys.

// SeaORM resolves foreign key dependencies and creates the tables in topological order.
// Requires the entity-registry and schema-sync feature flags.
db.get_schema_registry("my_crate::entity::*").sync(db).await;

Let SeaORM handle 95% of your transactional queries. For the remaining cases that are too complex to express, SeaORM still offers convenient support for writing raw SQL.

let user = Item { name: "Bob" }; // nested parameter access
let ids = [2, 3, 4]; // expanded by the .. operator

let user: Option<user::Model> = user::Entity::find()
    .from_raw_sql(raw_sql!(
        Sqlite,
        r#"SELECT "id", "name" FROM "user"
           WHERE "name" LIKE {user.name}
           AND "id" in ({..ids})
        "#
    ))
    .one(db)
    .await?;