sqlx

name	sqlx
description	Expert guide for using the SQLx Rust crate (async, pure Rust SQL toolkit). Use this skill when the user is working with SQL databases in Rust using SQLx.

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).

# 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.

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)

let row: (i64,) = sqlx::query_as("SELECT id FROM users WHERE email = $1")
    .bind("[e-mail]")
    .fetch_one(&pool).await?;

Compile-time Checked Query (Macros)

Requires DATABASE_URL environment variable or .env file.

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.

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.