Overview

SQLx is an async, pure Rust SQL crate featuring compile-time checked queries without a DSL. It supports PostgreSQL, MySQL, MariaDB, and SQLite. It is not an ORM but a toolkit for running raw SQL queries safely and efficiently.

Capabilities

•Compile-time verification: Checks queries against a live database at compile time using macros (query!, query_as!).
•Async/Await: Built from the ground up for async execution (tokio, async-std, actix).
•Database Agnostic: Supports multiple databases with a consistent API.
•Pure Rust: Drivers are written in pure Rust (except SQLite which links to C library).
•Connection Pooling: Built-in pooling with Pool.

Usage

Installation

Add sqlx to Cargo.toml with the necessary features (runtime + database).

toml

# Example: Tokio + Postgres
[dependencies]
sqlx = { version = "0.8", features = [ "runtime-tokio", "tls-native-tls", "postgres" ] }

Connection

Create a connection pool (recommended) or a single connection.

rust

use sqlx::postgres::PgPoolOptions;

let pool = PgPoolOptions::new()
    .max_connections(5)
    .connect("postgres://user:pass@localhost/db").await?;

Querying

Use sqlx::query (unprepared/prepared) or sqlx::query! (compile-time checked).

Runtime Query (Dynamic)

rust

let row: (i64,) = sqlx::query_as("SELECT id FROM users WHERE email = $1")
    .bind("user@example.com")
    .fetch_one(&pool).await?;

Compile-time Checked Query (Macros)

Requires DATABASE_URL environment variable or .env file.

rust

let countries = sqlx::query!(
        "SELECT country, count FROM countries WHERE organization = ?",
        organization
    )
    .fetch_all(&pool).await?;

Migrations

Add migrations with sqlx migrate add -r <description> (use underscores instead of spaces in description). After adding, update the SQL code in migrations/<timestamp>_<description>.up.sql and migrations/<timestamp>_<description>.down.sql. Run migrations with sqlx migrate run. See sqlx --help and sqlx migrate --help for more options.

rust

sqlx::migrate!("./migrations").run(&pool).await?;

References

•Documentation: docs.rs/sqlx (Primary API reference)
•Repository: github.com/launchbadge/sqlx (Examples, FAQ)
•Examples: See the examples/ directory in the repository for patterns.