Database models

Add validated CRUD and SQLx row decoding to your model.

Use SQLx 0.9 and Tokio with SQLite, PostgreSQL or MySQL. Enable sqlite for bundled SQLite, postgres for PostgreSQL, or mysql for MySQL. Each driver enables the shared sqlx integration. Server drivers enable Rustls TLS support and have no SQLite dependency:

[dependencies]
rydantic = { version = "=0.7.0", features = ["axum", "sqlite"] }
tokio = { version = "1", features = ["macros", "rt-multi-thread"] }

use rydantic::{Model, SqlModel, sqlx::sqlite::SqlitePoolOptions};

#[derive(Debug, PartialEq, Model, SqlModel)]
#[sql(table = "users")]
struct User {
    #[sql(primary_key, auto_increment)]
    id: Option<i64>,
    #[model(trim, min_length = 2)]
    #[sql(unique)]
    name: String,
    #[model(ge = 18)]
    #[sql(index)]
    age: u8,
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let pool = SqlitePoolOptions::new()
        .max_connections(1)
        .connect("sqlite::memory:")
        .await?;
    User::migrate(&pool).await?;

    let user = User::parse_json(r#"{"name":" Alice ","age":25}"#)?;
    let mut stored = user.insert(&pool).await?;
    let id = stored.id.expect("generated primary key");
    assert_eq!(User::get(&pool, &id).await?.as_ref(), Some(&stored));
    stored.age = 30;
    let updated = stored.update(&pool).await?;
    assert_eq!(updated.age, 30);
    assert!(User::delete(&pool, &id).await?);
    Ok(())
}

Derive Model and SqlModel together. Model supplies JSON/Serde/schema/validation behavior; SqlModel adds table metadata, a validated SQLx FromRow implementation, and asynchronous persistence operations. Each table has one primary key and uses a concrete owned struct with named fields. SQLx is re-exported through rydantic::sqlx.

SQL attribute	Behavior
#[sql(table = "users")]	Set the table name; the default is the struct name in snake_case
#[sql(primary_key)]	Declare the single primary-key field
#[sql(auto_increment)]	Generate an i64 or Option<i64> primary key when its value is zero or None
#[sql(rename = "display_name")]	Set the database column name independently of JSON aliases
#[sql(rename_from = "name")]	Rename a previous database column while preserving its data
#[sql(default = "pending")]	Set a constant SQL default and backfill a new required column
#[sql(unique)]	Generate a database uniqueness constraint
#[sql(index)]	Generate an index together with the table
#[sql(length = 256)]	Set a MySQL VARCHAR/VARBINARY bound; otherwise use model max_length, or 191 for indexed text/binary columns
#[sql(references = "users.id", on_delete = "cascade")]	Add a foreign key; deletion policies include no_action, restrict, cascade, and set_null (requires a nullable non-key column)
#[sql(skip)]	Keep a local field outside the table; provide a model default or optional field for row decoding

SQL identifiers are checked at compile time and quoted in generated statements. CRUD and filter values use bound parameters. Column metadata is exposed as User::COLUMNS; create_table_sql::<DB>() and create_index_sql::<DB>() expose generated DDL for an explicit driver.

Continue with PostgreSQL and MySQL, queries and transactions, or automatic migrations.