SQLx

🧰 The Rust SQL Toolkit

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SQLx is an async, pure Rust_† SQL crate featuring compile-time checked queries without a DSL. - **Truly Asynchronous**. Built from the ground-up using async/await for maximum concurrency. - **Compile-time checked queries** (if you want). See [SQLx is not an ORM](#sqlx-is-not-an-orm). - **Database Agnostic**. Support for [PostgreSQL], [MySQL], [SQLite], and [MSSQL]. - **Pure Rust**. The Postgres and MySQL/MariaDB drivers are written in pure Rust using **zero** unsafe_†† code. - **Runtime Agnostic**. Works on different runtimes ([`async-std`] / [`tokio`] / [`actix`]) and TLS backends ([`native-tls`], [`rustls`]). † The SQLite driver uses the libsqlite3 C library as SQLite is an embedded database (the only way we could be pure Rust for SQLite is by porting _all_ of SQLite to Rust). †† SQLx uses `#![forbid(unsafe_code)]` unless the `sqlite` feature is enabled. As the SQLite driver interacts with C, those interactions are `unsafe`. [postgresql]: http://postgresql.org/ [sqlite]: https://sqlite.org/ [mysql]: https://www.mysql.com/ [mssql]: https://www.microsoft.com/en-us/sql-server --- - Cross-platform. Being native Rust, SQLx will compile anywhere Rust is supported. - Built-in connection pooling with `sqlx::Pool`. - Row streaming. Data is read asynchronously from the database and decoded on-demand. - Automatic statement preparation and caching. When using the high-level query API (`sqlx::query`), statements are prepared and cached per-connection. - Simple (unprepared) query execution including fetching results into the same `Row` types used by the high-level API. Supports batch execution and returning results from all statements. - Transport Layer Security (TLS) where supported ([MySQL] and [PostgreSQL]). - Asynchronous notifications using `LISTEN` and `NOTIFY` for [PostgreSQL]. - Nested transactions with support for save points. - `Any` database driver for changing the database driver at runtime. An `AnyPool` connects to the driver indicated by the URI scheme. ## Install SQLx is compatible with the [`async-std`], [`tokio`] and [`actix`] runtimes; and, the [`native-tls`] and [`rustls`] TLS backends. When adding the dependency, you must chose a runtime feature that is `runtime` + `tls`. [`async-std`]: https://github.com/async-rs/async-std [`tokio`]: https://github.com/tokio-rs/tokio [`actix`]: https://github.com/actix/actix-net [`native-tls`]: https://crates.io/crates/native-tls [`rustls`]: https://crates.io/crates/rustls ```toml # Cargo.toml [dependencies] # tokio + rustls sqlx = { version = "0.5", features = [ "runtime-tokio-rustls" ] } # async-std + native-tls sqlx = { version = "0.5", features = [ "runtime-async-std-native-tls" ] } ``` The runtime and TLS backend not being separate feature sets to select is a workaround for a [Cargo issue](https://github.com/rust-lang/cargo/issues/3494). #### Cargo Feature Flags - `runtime-async-std-native-tls`: Use the `async-std` runtime and `native-tls` TLS backend. - `runtime-async-std-rustls`: Use the `async-std` runtime and `rustls` TLS backend. - `runtime-tokio-native-tls`: Use the `tokio` runtime and `native-tls` TLS backend. - `runtime-tokio-rustls`: Use the `tokio` runtime and `rustls` TLS backend. - `runtime-actix-native-tls`: Use the `actix` runtime and `native-tls` TLS backend. - `runtime-actix-rustls`: Use the `actix` runtime and `rustls` TLS backend. - `postgres`: Add support for the Postgres database server. - `mysql`: Add support for the MySQL/MariaDB database server. - `mssql`: Add support for the MSSQL database server. - `sqlite`: Add support for the self-contained [SQLite](https://sqlite.org/) database engine. - `any`: Add support for the `Any` database driver, which can proxy to a database driver at runtime. - `macros`: Add support for the `query*!` macros, which allow compile-time checked queries. - `migrate`: Add support for the migration management and `migrate!` macro, which allow compile-time embedded migrations. - `uuid`: Add support for UUID (in Postgres). - `chrono`: Add support for date and time types from `chrono`. - `time`: Add support for date and time types from `time` crate (alternative to `chrono`, which is preferred by `query!` macro, if both enabled) - `bstr`: Add support for `bstr::BString`. - `git2`: Add support for `git2::Oid`. - `bigdecimal`: Add support for `NUMERIC` using the `bigdecimal` crate. - `decimal`: Add support for `NUMERIC` using the `rust_decimal` crate. - `ipnetwork`: Add support for `INET` and `CIDR` (in postgres) using the `ipnetwork` crate. - `json`: Add support for `JSON` and `JSONB` (in postgres) using the `serde_json` crate. - `tls`: Add support for TLS connections. - `offline`: Enables building the macros in offline mode when a live database is not available (such as CI). - Requires `sqlx-cli` installed to use. See [sqlx-cli/README.md][readme-offline]. [readme-offline]: sqlx-cli/README.md#enable-building-in-offline-mode-with-query ## SQLx is not an ORM! SQLx supports **compile-time checked queries**. It does not, however, do this by providing a Rust API or DSL (domain-specific language) for building queries. Instead, it provides macros that take regular SQL as an input and ensure that it is valid for your database. The way this works is that SQLx connects to your development DB at compile time to have the database itself verify (and return some info on) your SQL queries. This has some potentially surprising implications: - Since SQLx never has to parse the SQL string itself, any syntax that the development DB accepts can be used (including things added by database extensions) - Due to the different amount of information databases let you retrieve about queries, the extent of SQL verification you get from the query macros depends on the database **If you are looking for an (asynchronous) ORM,** you can check out [`ormx`] or [`SeaORM`], which is built on top of SQLx. [`ormx`]: https://crates.io/crates/ormx [`SeaORM`]: https://github.com/SeaQL/sea-orm ## Usage See the `examples/` folder for more in-depth usage. ### Quickstart ```toml [dependencies] # PICK ONE: # Async-std: sqlx = { version = "0.5", features = [ "runtime-async-std-native-tls", "postgres" ] } async-std = { version = "1", features = [ "attributes" ] } # Tokio: sqlx = { version = "0.5", features = [ "runtime-tokio-native-tls" , "postgres" ] } tokio = { version = "1", features = ["full"] } # Actix-web: sqlx = { version = "0.5", features = [ "runtime-actix-native-tls" , "postgres" ] } actix-web = "3" ``` ```rust use sqlx::postgres::PgPoolOptions; // use sqlx::mysql::MySqlPoolOptions; // etc. #[async_std::main] // or #[tokio::main] // or #[actix_web::main] async fn main() -> Result<(), sqlx::Error> { // Create a connection pool // for MySQL, use MySqlPoolOptions::new() // for SQLite, use SqlitePoolOptions::new() // etc. let pool = PgPoolOptions::new() .max_connections(5) .connect("postgres://postgres:password@localhost/test").await?; // Make a simple query to return the given parameter (use a question mark `?` instead of `$1` for MySQL) let row: (i64,) = sqlx::query_as("SELECT $1") .bind(150_i64) .fetch_one(&pool).await?; assert_eq!(row.0, 150); Ok(()) } ``` ### Connecting A single connection can be established using any of the database connection types and calling `connect()`. ```rust use sqlx::Connection; let conn = SqliteConnection::connect("sqlite::memory:").await?; ``` Generally, you will want to instead create a connection pool (`sqlx::Pool`) in order for your application to regulate how many server-side connections it's using. ```rust let pool = MySqlPool::connect("mysql://user:pass@host/database").await?; ``` ### Querying In SQL, queries can be separated into prepared (parameterized) or unprepared (simple). Prepared queries have their query plan _cached_, use a binary mode of communication (lower bandwidth and faster decoding), and utilize parameters to avoid SQL injection. Unprepared queries are simple and intended only for use case where a prepared statement will not work, such as various database commands (e.g., `PRAGMA` or `SET` or `BEGIN`). SQLx supports all operations with both types of queries. In SQLx, a `&str` is treated as an unprepared query and a `Query` or `QueryAs` struct is treated as a prepared query. ```rust // low-level, Executor trait conn.execute("BEGIN").await?; // unprepared, simple query conn.execute(sqlx::query("DELETE FROM table")).await?; // prepared, cached query ``` We should prefer to use the high level, `query` interface whenever possible. To make this easier, there are finalizers on the type to avoid the need to wrap with an executor. ```rust sqlx::query("DELETE FROM table").execute(&mut conn).await?; sqlx::query("DELETE FROM table").execute(&pool).await?; ``` The `execute` query finalizer returns the number of affected rows, if any, and drops all received results. In addition, there are `fetch`, `fetch_one`, `fetch_optional`, and `fetch_all` to receive results. The `Query` type returned from `sqlx::query` will return `Row<'conn>` from the database. Column values can be accessed by ordinal or by name with `row.get()`. As the `Row` retains an immutable borrow on the connection, only one `Row` may exist at a time. The `fetch` query finalizer returns a stream-like type that iterates through the rows in the result sets. ```rust // provides `try_next` use futures::TryStreamExt; let mut rows = sqlx::query("SELECT * FROM users WHERE email = ?") .bind(email) .fetch(&mut conn); while let Some(row) = rows.try_next().await? { // map the row into a user-defined domain type let email: &str = row.try_get("email")?; } ``` To assist with mapping the row into a domain type, there are two idioms that may be used: ```rust let mut stream = sqlx::query("SELECT * FROM users") .map(|row: PgRow| { // map the row into a user-defined domain type }) .fetch(&mut conn); ``` ```rust #[derive(sqlx::FromRow)] struct User { name: String, id: i64 } let mut stream = sqlx::query_as::<_, User>("SELECT * FROM users WHERE email = ? OR name = ?") .bind(user_email) .bind(user_name) .fetch(&mut conn); ``` Instead of a stream of results, we can use `fetch_one` or `fetch_optional` to request one required or optional result from the database. ### Compile-time verification We can use the macro, `sqlx::query!` to achieve compile-time syntactic and semantic verification of the SQL, with an output to an anonymous record type where each SQL column is a Rust field (using raw identifiers where needed). ```rust let countries = sqlx::query!( " SELECT country, COUNT(*) as count FROM users GROUP BY country WHERE organization = ? ", organization ) .fetch_all(&pool) // -> Vec<{ country: String, count: i64 }> .await?; // countries[0].country // countries[0].count ``` Differences from `query()`: - The input (or bind) parameters must be given all at once (and they are compile-time validated to be the right number and the right type). - The output type is an anonymous record. In the above example the type would be similar to: ```rust { country: String, count: i64 } ``` - The `DATABASE_URL` environment variable must be set at build time to a database which it can prepare queries against; the database does not have to contain any data but must be the same kind (MySQL, Postgres, etc.) and have the same schema as the database you will be connecting to at runtime. For convenience, you can use [a `.env` file][dotenv] to set DATABASE_URL so that you don't have to pass it every time: ``` DATABASE_URL=mysql://localhost/my_database ``` [dotenv]: https://github.com/dotenv-rs/dotenv#examples The biggest downside to `query!()` is that the output type cannot be named (due to Rust not officially supporting anonymous records). To address that, there is a `query_as!()` macro that is mostly identical except that you can name the output type. ```rust // no traits are needed struct Country { country: String, count: i64 } let countries = sqlx::query_as!(Country, " SELECT country, COUNT(*) as count FROM users GROUP BY country WHERE organization = ? ", organization ) .fetch_all(&pool) // -> Vec .await?; // countries[0].country // countries[0].count ``` To avoid the need of having a development database around to compile the project even when no modifications (to the database-accessing parts of the code) are done, you can enable "offline mode" to cache the results of the SQL query analysis using the `sqlx` command-line tool. See [sqlx-cli/README.md](./sqlx-cli/README.md#enable-building-in-offline-mode-with-query). Compile time verified queries do quite a bit of work at compile time. Incremental actions like `cargo check` and `cargo build` can be significantly faster when using an optimized build by putting the following in your `Cargo.toml` (More information in the [Profiles section](https://doc.rust-lang.org/cargo/reference/profiles.html) of The Cargo Book) ```toml [profile.dev.package.sqlx-macros] opt-level = 3 ``` ## Safety This crate uses `#![forbid(unsafe_code)]` to ensure everything is implemented in 100% Safe Rust. If the `sqlite` feature is enabled, this is downgraded to `#![deny(unsafe_code)]` with `#![allow(unsafe_code)]` on the `sqlx::sqlite` module. There are several places where we interact with the C SQLite API. We try to document each call for the invariants we're assuming. We absolutely welcome auditing of, and feedback on, our unsafe code usage. ## License Licensed under either of - Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0) - MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT) at your option. ## Contribution Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.