Supported databases

Database	Use case
PostgreSQL	Production — recommended for most applications
MySQL	Production — high-traffic workloads, existing MySQL infrastructure
SQLite	Development / embedded — zero setup, single file

ORM choices

SQLx

SQLx provides compile-time checked SQL queries. Your queries are verified against the actual database schema at build time — if a column doesn’t exist, the build fails.

let user = sqlx::query_as!(
    User,
    "SELECT id, email, created_at FROM users WHERE id = $1",
    user_id
)
.fetch_one(&pool)
.await?;

Pros: Maximum type safety, minimal overhead, raw SQL control. Cons: Requires a live database or saved metadata (sqlx prepare) to compile.

SeaORM

SeaORM is a fully async dynamic ORM built on top of SQLx. It provides an ActiveRecord-style API and a migration system.

let user = User::find_by_id(user_id)
    .one(&db)
    .await?
    .ok_or(AppError::NotFound)?;

Pros: Migrations, entity generation, no SQL required. Cons: More abstraction, slightly higher compile times.

Configuring the connection

Set DATABASE_URL in your .env:

# PostgreSQL
DATABASE_URL=postgres://user:password@localhost:5432/mydb

# MySQL
DATABASE_URL=mysql://user:password@localhost:3306/mydb

# SQLite
DATABASE_URL=sqlite:./dev.db

Running migrations

With SQLx:

# Install the CLI
cargo install sqlx-cli

# Create and run migrations
sqlx migrate add create_users_table
sqlx migrate run

With SeaORM:

cargo install sea-orm-cli
sea-orm-cli migrate generate create_users_table
sea-orm-cli migrate up