Database Setup

Opening a database connection in Toasty has two steps: register your models, then connect to a database. Db::builder() handles both.

let mut db = toasty::Db::builder()
    .models(toasty::models!(User, Post))
    .connect("sqlite::memory:")
    .await?;

Registering models

The models! macro builds a ModelSet — the collection of model definitions Toasty uses to generate the database schema. It accepts three forms, which can be combined freely:

toasty::models!(
    // All models from the current crate
    crate::*,
    // All models from an external crate
    third_party_models::*,
    // Individual models
    User,
    other_module::Post,
)

crate::* finds all #[derive(Model)] and #[derive(Embed)] types in your crate at compile time. This is the simplest option when all your models live in one crate.

You don’t need to list every model. Registering a model also registers any models reachable through its fields — BelongsTo, HasMany, HasOne, and embedded types are all discovered by traversing the model’s fields. For example, if User has a HasMany<Post> field and Post has a BelongsTo<User> field, toasty::models!(User) registers both User and Post.

Connection URLs

The connection URL determines which database driver Toasty uses. Each driver requires its corresponding feature flag in Cargo.toml.

Examples:

// In-memory SQLite
.connect("sqlite::memory:")

// SQLite file
.connect("sqlite://path/to/db.sqlite")

// PostgreSQL
.connect("postgresql://user:pass@localhost:5432/mydb")

// MySQL
.connect("mysql://user:pass@localhost:3306/mydb")

// DynamoDB (uses AWS config from environment)
.connect("dynamodb://us-east-1")

Using a driver directly

If you need more control over the driver configuration, construct the driver yourself and pass it to build() instead of connect():

let driver = toasty_driver_sqlite::Sqlite::in_memory();
let mut db = toasty::Db::builder()
    .models(toasty::models!(User))
    .build(driver)
    .await?;

Table name prefix

To prefix all generated table names (useful when multiple services share a database), call table_name_prefix() on the builder:

let mut db = toasty::Db::builder()
    .models(toasty::models!(crate::*))
    .table_name_prefix("myapp_")
    .connect("sqlite::memory:")
    .await?;